The purpose of the present invention is to increase elimination efficiency for oil in an oil separator that separates and eliminates oil from gas containing oil as an impurity. This oil separator is characterized by having a cylindrical first filter member (42) that is fabricated from cylindrical filter material having air permeability and is disposed such that a target gas flows in from the hollow part thereof and also such that the center axis thereof is in the vertical direction and a second filter member (43) that is fabricated from filter material having air permeability and surrounds the outside surface of the first filter member (42) with a prescribed gap from the outside surface of the first filter member (42).
