A screw compressor is provided with: a compressor body in which a screw rotor is accommodated in a rotor casing; a motor in which a rotator and a stator are accommodated in a motor chamber, the motor for rotationally driving a rotor shaft through use of a motor shaft; axial liquid supplying parts, provided on an anti-rotor side of the motor shaft; a motor shaft cooling part which is a cavity extending in the axial direction inside the motor shaft, the motor shaft cooling part for cooling the motor shaft by circulating a cooling liquid through the inside of the cavity thereof; and a liquid outlet part positioned on a rotor side of the motor shaft or a motor side of the rotor shaft and fluidically connected to the motor shaft cooling part so as to extend radially inward from an outlet opening formed in an outer surface of the motor shaft or the rotor shaft.