In an oil-cooled screw compressor comprising, a compressor body including a pair of a male rotor and a female rotor, a motor including a stator and a motor rotor connected to one of the male and female rotors, and an oil separator container for gathering the oil from a mixture of the gaseous manner and oil to restrain the oil from proceeding with the compressed gaseous matter after the mixture of the gaseous manner and oil is discharged from the pair of male and female rotors, a rotational axis of the motor rotor and the rotational axis of the one of the male and female rotors are coaxial with respect to each other.