A refrigerant compressor for use with an air conditioner for vehicles, which comprises a housing in which a vane pump is accommodated, and a covering disposed so as to enclose said housing in a fashion that its inner wall cooperates with the outer wall of said housing to define a refrigerant delivery chamber, characterized by that a temperature sensor is embedded in a portion of the outer wall of said housing. The sensor may be composed of a semiconductor thermo-sensitive device or a conductor wire made of a metal including a high resistance metal. Thus, accurate and stable detection of the internal temperature of the compressor is feasible, thereby making it possible to avoid seizure of the sliding machine parts of the compressor.