A slant plate type compressor (10) including a compressor housing (20) having a cylinder block (21) is disclosed. A plurality of peripherally located cylinders (70) are formed through the cylinder block. A piston (71) is slidably fitted in each of the cylinders (70) and is reciprocated by a drive mechanism which includes a slant plate (50). The slant plate (50) includes a boss (54) for mounting a balance weight ring thereon. The balance weight ring (500) includes an annular depression formed at an inner peripheral portion thereof. The balance weight ring (500) is firmly attached to the boss (54) by different types of retaining means.
