To prevent breakage of piping and an accident accompanying the breakage by positively detecting an abnormal rise in refrigerant pressure and stopping operation of a compressor in a sealed electric compressor for a refrigerant.

A fuse element 6 disposed in series with a motor 1 and a power source 4 of the electric compressor melts down by a current sufficiently larger than the operation current of the motor, and a normally-off type pressure switch 7 is disposed to be electrically parallel to a main winding 3A of the motor 1. When the refrigerant pressure becomes abnormally high, the pressure switch 7 is activated to short-circuit the main winding 3A. The fuse element 6 melts down by this short-circuit and interrupts conduction of electricity. The operation of the electric compressor can thereby be positively stopped before the piping and a pressure container are damaged by the abnormal pressure.