Altmaier was born on 18 June 1958 in Ensdorf, Saarland. He is the son of a coal miner and a nurse. He studied law at Saarland University.
In addition to his native German, he speaks English, Dutch and French fluently. He is known for his intellect, which some "feel intimidated by".
Altmaier began his career as a research assistant for public and international law at Saarland University in 1995 and later at the European Institute of Saarland University. His tenure lasted until 2000. He worked for the Directorate-General for Employment and Social Affairs of the European Commission from 1990 to 1994.
Altmaier has been a member of the CDU since 1976.
Altmaier has been a member of the Bundestag since the 1994 national elections. Between 1994 and 2002, he served on the Committee on Legal Affairs and the Committee on Affairs of the European Union, where he was his parliamentary group’s rapporteur on matters related to the Charter of Fundamental Rights of the European Union.
When the Bundestag created a committee to examine whether then-Chancellor Gerhard Schröder and others in the governing SPD party inflated economic figures before the 2002 federal elections to hide a growing budget deficit, he was chosen by his parliamentary group to lead the inquiry.
From 2006 to 2011 Altmaier was president of Europa-Union Deutschland, the German section of the Union of European Federalists.
Following the 2005 federal elections, Altmaier became Parliamentary State Secretary in the Federal Ministry of the Interior under Wolfgang Schäuble. In this capacity, he publicly admitted in 2009 that Germany followed a request of the government of Saudi Arabia it to grant influential cleric Abdullah Ibn Jibreen police protection in a Berlin hospital where he was undergoing heart treatment; the decision garnered sharp criticism from the opposition parties, with the Green Party questioning why Germany hosted someone who "has called for the killing of Shiites [and] praised Osama bin Laden."
In 2009, Altmaier was mentioned by international media as potential candidate for the office of European Commissioner.
Succeeding Norbert Röttgen as parliamentary secretary (chief whip) of the CDU/CSU parliamentary group in the Bundestag following the 2009 elections, Altmaier was in charge of negotiating the passage of Eurozone crisis legislation through the parliament. He served as the government’s chief negotiator with the opposition Social Democrats and Greens, as well as with potential rebels from the government benches.
In 2012, Altmaier also served as chairman of the Parliamentary Control Panel (PKGr), which provides parliamentary oversight of Germany’s intelligence services BND, BfV and MAD.
On 22 May 2012, Altmaier replaced Norbert Röttgen as Federal Minister for the Environment, Nature Conservation and Nuclear Safety in the second Merkel cabinet.
While in office, Altmaier coordinated the government's efforts to exit nuclear power generation by 2022 and rely on more renewable sources such as wind and solar ("Energiewende"). He also demanded companies to harvest metals including rare earths from recycled electronics as Germany sought to become less dependent on imports from China and other nations. Together with his French counterpart Delphine Batho, he put in motion the establishment of the French-German Office for Renewable Energies (L'Office franco-allemand pour les énergies renouvelables) in 2013.
In 2012, Altmaier led the German delegation to the 2012 United Nations Climate Change Conference in Doha.
In 2013, Altmaier and Economics Minister Philipp Rösler reached agreement on far-reaching regulations for the fracking industry.
In the negotiations to form a government following the 2013 federal elections, Altmaier led the CDU/CSU delegation in the energy working group; his co-chair from the SPD was Hannelore Kraft, Minister-President of North Rhine-Westphalia. In Angela Merkel's third Cabinet he serves as the Chief of Staff of the Federal Chancellery and a Federal Minister for Special Affairs. In this capacity, he is also in charge of co-ordinating Germany’s intelligence services.
In July 2015, Altmaier invited the United States Ambassador to Germany, John B. Emerson, to explain documents publicized by WikiLeaks that showed what appeared to be summaries of recorded conversations involving Chancellor Merkel or senior officials. Shortly after, WikiLeaks released additional documents including Altmaier’s telephone number, adding to a growing pile of allegations that United States intelligence agencies conducted extensive surveillance of the German government.
In October 2015, Merkel put Altmaier in charge of coordinating Germany's response to the refugee crisis. Since early 2017, he has been a member of the German government's cabinet committee on Brexit at which ministers will discuss organizational and structural issues related to the United Kingdom's departure from the European Union.
Altmaier belongs to the more liberal wing of the CDU.
Responding to a growing unease over Germany's role in bailing out highly indebted European states, Altmaier in 2011 demanded that states that violate the EU's Stability and Growth Pact should be subject to the European Court of Justice. That same year, he advised against Germany pursuing a prompt debt haircut for Greece and warned of the consequences. According to Altmaier, the banks must be supported, in Greece and elsewhere, and the European Financial Stability Facility might have to issue guarantees for the holders of Italian and Spanish bonds, because they also fear that they will be asked to pay up.Europa-Union Deutschland, President (2005–2009), Honorary President (since 2009)
European Movement Germany, Vice-President (2002–2009)
German Institute for International and Security Affairs (SWP), Vice Chairman of the Council
KfW, Ex-Officio Member of the Board of Supervisory Directors (2013)
Institute for European Politics, Member of the Board of Trustees (2005–2009)
ZDF, Ex-officio Member of the Television Board (2002–2005)