PURPOSE: To make a refrigerant compressor light in weight with enhanced heat resistance by forming its rotor with bearing parts solidly from ceramic, inserting a shaft from one side of the rotor, and by fastening them from the other side using a bolt.

CONSTITUTION: A rotor 10 of ceramic has bearing parts 10a, 10b is supported by a front 11 and a rear 12 side plate. Part of a shaft 13 is inserted in the rotor 10 at its central part from one side of the rotor, and they are fastened solidly by driving a bolt 14 from behind the rotor 10. Accordingly the weight of the rotor is reduced as well as its durability is not impaired by temp. rise, to accomplish a rotary compressor with excellent performance.