A compressor, which includes: a driving shaft including a swash plate which is rotated in a swash plate chamber inside the compressor and is mounted slantly on the driving shaft and a main refrigerant suction flow channel formed therein so that refrigerant inhaled into the swash plate chamber passes through the swash plate and moves toward cylinder bores (131, 141); front and rear cylinder blocks (130, 140) respectively having shaft support holes (133, 143) to which the driving shaft is rotatably mounted, a plurality of the cylinder bores (131, 141) formed at both sides of the swash plate chamber, and suction passageways (132, 142) for fluidically communicating the shaft support holes (133, 143) and the cylinder bores (131, 141) with each other so that the refrigerant inhaled into the main refrigerant suction flow channel of the driving shaft is inhaled into the cylinder bores (131, 141) in order during rotation of the driving shaft; a plurality of pistons mounted on the outer periphery of the swash plate in such a manner as to interpose a shoe between the piston and the swash plate, for performing a reciprocating motion inside the cylinder bores (131, 141) while communicating with the rotation of the swash plate; front and rear housings (110, 120) coupled with both sides of the front and rear cylinder blocks (130, 140) and respectively having discharge chambers (111, 121) formed therein; and valve units interposed between the front and rear cylinder blocks (130, 140) and the front and rear housings (110, 120), wherein when the diameter of the main refrigerant suction flow channel is A and the hydraulic diameter of an inlet of the main refrigerant suction flow channel is B, suction resistivity of the inlet of the main refrigerant suction flow channel is defined as the following formula "B/A", and satisfies the following formula: 0.5≤R≤1.3, and wherein the rear housing further includes a refrigerant storage chamber, and the cylinder block further includes an auxiliary refrigerant suction flow channel for fluidically communicating the swash plate chamber and the refrigerant storage chamber with each other. a driving shaft including a swash plate which is rotated in a swash plate chamber inside the compressor and is mounted slantly on the driving shaft and a main refrigerant suction flow channel formed therein so that refrigerant inhaled into the swash plate chamber passes through the swash plate and moves toward cylinder bores (131, 141); front and rear cylinder blocks (130, 140) respectively having shaft support holes (133, 143) to which the driving shaft is rotatably mounted, a plurality of the cylinder bores (131, 141) formed at both sides of the swash plate chamber, and suction passageways (132, 142) for fluidically communicating the shaft support holes (133, 143) and the cylinder bores (131, 141) with each other so that the refrigerant inhaled into the main refrigerant suction flow channel of the driving shaft is inhaled into the cylinder bores (131, 141) in order during rotation of the driving shaft; a plurality of pistons mounted on the outer periphery of the swash plate in such a manner as to interpose a shoe between the piston and the swash plate, for performing a reciprocating motion inside the cylinder bores (131, 141) while communicating with the rotation of the swash plate; front and rear housings (110, 120) coupled with both sides of the front and rear cylinder blocks (130, 140) and respectively having discharge chambers (111, 121) formed therein; and valve units interposed between the front and rear cylinder blocks (130, 140) and the front and rear housings (110, 120), wherein when the diameter of the main refrigerant suction flow channel is A and the hydraulic diameter of an inlet of the main refrigerant suction flow channel is B, suction resistivity of the inlet of the main refrigerant suction flow channel is defined as the following formula "B/A", and satisfies the following formula: 0.5≤R≤1.3, and wherein the rear housing further includes a refrigerant storage chamber, and the cylinder block further includes an auxiliary refrigerant suction flow channel for fluidically communicating the swash plate chamber and the refrigerant storage chamber with each other.