A screw compressor includes a screw rotor, a gate rotor, and a casing that form a compression chamber. A case outlet is formed in a case outer wall of the casing. A discharge port communicates with the case outlet, and is formed in a portion of the casing facing the compression chamber. The discharge port has first and second end on first and second opposite sides in the axial direction. The case outlet is located between a first position away from the first end toward the first side in the axial direction by a radius of the gate and a second position away from the second end toward the second side in the axial direction by the radius of the gate. The case outlet is located closer to the discharge port than to the screw rotor in the radial direction.