Compressor

A compressor comprising:

• a rotary shaft;
• a housing housing the rotary shaft and having a suction port through which a suction fluid is drawn in and a discharge port through which a compression fluid is discharged;
• a first compression chamber and a second compression chamber formed to introduce therein the suction fluid, respective volumes of the first compression chamber and the second compression chamber being periodically changed with rotation of the rotary shaft, and phases of changes of the respective volumes being mutually shifted;
• and
• a communication mechanism switched between a communicating state in which the first compression chamber and the second compression chamber communicate with each other, and a non-communicating state in which the first compression chamber and the second compression chamber do not communicate with each other,
• wherein a cycle movement is performed that includes parallel compression operation in which compression of fluid is performed in the compression chambers in the communicating state.