A cyclone-type separator comprises a hollow cylindrical main body in to which liquid containing foreign matter is introduced, a clean room provided in an upper end of the main body, a communication pipe which connects the clean room to an interior of the main body, and a porous separating pipe arranged in the clean room. As the liquid swirls in the main body, an eddy stream is generated. A columnar air layer and a clean liquid layer are formed, both aligned with the centerline of the eddy stream. The air layer and the liquid layer are guided via the communication pipe into the separating pipe. At the bottom of the clean room, there are provided a first reservoir for storing the liquid coming through the separating pipe, a second reservoir for storing the liquid flowing from the first reservoir, and a coolant outlet port for discharging the clean liquid.