PURPOSE: To make it possible to very capacity of a rotary compressor easily, by forming an electro-magnetic coil part which generates magnetic force capable of restricting the motion of a blade, on a main bearing or a subbearing, at a part which confronts the blade.

CONSTITUTION: Plural stator coil slots aWf are formed on a main bearing 21, in those positions which confront a blade 28, and an electro-magnetic coil part is constituted through stator coils 32 around said slots aWf. On the other hand, rotor bars 31 are arranged on the blade 28, in those portions which confront said electro-magnetic coil part, and constitute a linear motor with this electro-magnetic coil part. In this way, the blade 28 can be restricted easily by changing the running direction of the linear motor, and consequently, capacity of the rotary compressor can be controlled easily.