Abstract: Thermostat comprises a heat sensitive body of ferromagnetic material and a movable magnet cooperating therewith. A pair of a contacts which are closed or open depending upon the position of the magnet are provided where the position in turn depends upon the temperature dependant magnetic properties of the sensitive body. The magnet is exposed to a counter force, that is oppositely directed to the attraction force, and a spring force on a pair of contacts has a contact making action in one position of the magnet and a contact opening action in another position of the magnet. More particularly the counter force and the spring force are exerted by one and the same snap spring, that acts between the movable contact formed as a contact tongue and the magnet.