A compressor incorporated with an oil separator having a separation chamber and communication holes. The separation chamber is placed adjacent to a discharge chamber, has a space formed in the entire inside of the separation chamber, separates oil-containing gas, which is introduced into the separation chamber, into gas and oil by centrifugal separation, allows the separated oil to drop downward, and upwardly extracts the separated gas. The communication holes interconnect the discharge chamber and the separation chamber and introduce the oil-containing gas, coming from the discharge chamber, into the separation chamber. The communication holes are arranged in the separation chamber, in a direction extending from a gas release side to an oil drop side. The structure of an oil separation section is simplified to improve productivity and reduce cost, and a high degree of design freedom of the position of a discharge port is obtained.