Abstract: The present invention relates to a microvalve usable primarily as a pilot lve in pneumatic controls. The prior art solenoid valves used in this field can be miniaturized only at considerably high cost. The microvalve of the invention consists of a first part (1), on the pressure side, with a diaphragm structure (3) as the movable closing component and a second part (2) with an outlet aperture (7) and a seat (5). The diaphragm structure has heating elements and is coated on one side with a material with differing coefficients of heat expansion, in such a way that heating causes the diaphragm to bend against the pressure applied on it. At least one of the two parts has a recess (6) of defined depth arranged in such a way that with the valve closed hollows are formed which are heated by the heating elements. The microvalve described can economically produced with semiconductor technology means and has improved switching properties on account of its combined thermo-mechanical/thermo-pneumatic method of operation.