PURPOSE: To increase the release rate of a rotary compressor, by making an opening of a release hole open to a bearing or a cylinder larger than the opening of a valve seat port of a check valve.

CONSTITUTION: A forward end section of a release pipe 17 is connected to the base section of a valve support 21 to form a release system 16 with the insides of the valve support 21 and the release pipe 17 serving as a release path 27. As a release system 15 has a recess 25b, the opening of a release hole 26 is substantially larger than the diameter of an opening of a valve seat port 23b. Thus since the position of the release hole can be moved as such to the high pressure side, much release can be performed to correspond to the delay.