A reciprocating compressor includes: a reciprocating motor, an outer stator and an inner stator provided with at least one step portion at both sides thereof, and an armature linearly moving therebetween; a compression unit having a cylinder and a piston inserted in the cylinder to receive a linear and reciprocal driving force of the reciprocating motor and compress a gas; a suction unit sucking a gas into the compression unit; a discharge unit discharging the gas compressed in the compression unit to outside the container; a resonance spring unit elastically supporting the piston and the armature; and a frame unit supporting the compression unit and the reciprocating motor. Because stable driving is achieved in its operation, generation of vibration and noise can be minimized, heightening reliability. In addition, the amount of gas discharge can be accurately controlled.