There is provided a vane compressor which prevents leakage of refrigerant gas by decreasing the number of airtight interfaces between component parts and prevents seizure from occurring between its rotor and its side block without surface treatment of the side block. The vane compressor has a cam ring. The rotor is rotatably received in the cam ring. A first head is secured to one end face of the cam ring. A second head is secured to another end face of the cam ring in a manner such that the second head closes an opening of the another end face of the cam ring and one end face of the rotor can be brought into contact with the second head. The side block is received in the first head in a manner such that it closes an opening of the one end face of the cam ring and another end face of the rotor can be brought into contact with the side block.