The Federal Department of Environment, Transport, Energy and Communications (DETEC, German: Eidgenössisches Departement für Umwelt, Verkehr, Energie und Kommunikation, French: Département fédéral de l'environnement, des transports, de l'énergie et des communications, Italian: Dipartimento federale dell'ambiente, dei trasporti, dell'energia e delle comunicazioni, Romansh: Departament federal per ambient, traffic, energia e communicaziun^ⓘ) is one of the seven departments of the Swiss federal government, headed by a member of the Swiss Federal Council.

The department is composed of the following offices:^[2]

• General Secretariat
• Federal Office for Spatial Development (ARE): Coordinates area planning between the federal agencies, the cantons and the municipalities.
• Federal Office for the Environment (FOEN): Responsible for matters of the environment, including the protection of plants and animals and the protection against noise, air pollution or natural hazards.
• Federal Office for Civil Aviation (FOCA): Regulates civil aviation.
• Federal Office of Communications (OFCOM): Regulates radio and TV stations, notably the Swiss Broadcasting Corporation.
• Federal Office of Energy (FOE): Responsible for the provision of electrical energy at the federal level, as well as for the supervision of dams.
• Federal Office of Transport (FOT): Responsible for public transport at the federal level, including the development of the federal rail network and navigation on the Rhine.
• Federal Roads Office (FEDRO): Responsible for the construction, maintenance and operation of the national highway network.

The following independent authorities are affiliated to the DETEC for administrative purposes:

• Swiss Transportation Safety Investigation Board (STSB, formerly Aircraft Accident Investigation Bureau and Investigation Bureau for Railway, Funicular and Boat Accidents).
• Federal Communications Commission (ComCom): Regulates the telecommunications market, awards service licences, rules on interconnection disputes and approves frequency and numbering plans.
• Federal Electricity Commission (ElCom): monitors electricity prices, rules as a judicial authority on disputes relating to network access and payment of cost-covering feed-in of electricity produced from renewable energy, monitors electricity supply security and regulates issues relating to international electricity transmission and trading.
• Federal Postal Services Commission (PostCom): Regulates the Swiss Post and Swiss postal market.
• Rail Transport Commission (RailCom): Arbitrates in disputes over access to the rail network and the calculation of fees for the use of infrastructure.
• Independent Complaints Authority for Radio and Television (ICA): Decides on complaints related to radio and television programmes.
• Safety Office (formerly known as the Civil Aviation Safety Office, CASO): supports the development of safety in land, sea and air transport, in the use, transport and distribution of energy, and for communications infrastructures
• Reporting Office for Just Culture in Civil Aviation (ROJCA): strengthens Just Culture through the protection of the information source of an occurrence reporting in Swiss Civil Aviation.
• Federal Inspectorate for Heavy Current Installations (ESTI): Responsible for inspecting low and heavy-current electrical installations.
• Swiss Federal Nuclear Safety Inspectorate (ENSI): Assesses and monitors security and radiation protection in Swiss nuclear installations.
• Federal Pipelines Inspectorate (ERI): Responsible for the planning, construction and operation of fuel pipeline systems in Switzerland and Liechtenstein.

• The building of the Federal Office of Civil Aviation, the Federal Roads Office and the Federal Office of Energy

• 1848–1859: Department of Posts and Construction
• 1860–1872: Department of Posts
• 1873–1878: Department of Posts and Telegraph
• 1879–1962: Department of Posts and Railways
• 1963–1978: Department of Transport, Communications and Energy
• 1979–1997: Federal Department of Transport, Communications and Energy
• Since 1998: Federal Department of Environment, Transport, Energy and Communications

• Energy in Switzerland