A scroll compressor according to the present invention includes a casing, an orbiting member provided within the casing and performing an orbiting motion, a non-orbiting member forming a compression chamber together with the orbiting member, the compression chamber having a suction chamber, an intermediate pressure chamber and a discharge chamber, a communication passage communicating inside and outside of the compression chamber with each other, an opening/closing valve assembly provided outside the non-orbiting member within the casing and opening and closing the communication passage, and a switching valve assembly provided within the casing and operating the opening/closing valve assembly, whereby a facilitated fabrication, improved valve responsiveness and a relaxed restriction for a specification of a valve can be achieved, and also an over-compression can be prevented by an installation of a check valve, and an assembling efficiency can be improved by installing two valve assemblies outside the non-orbiting member.