A compressor comprises a discharge valve which is provided so as to be coupled to a fixed scroll and open/close a discharge hole. The discharge valve includes a coupling portion which is coupled to one surface of the fixed scroll, the surface facing a muffler, and a head portion extending from the coupling portion and opening/closing the discharge hole. The head portion may be provided with a communicating hole for allowing the discharge hole and the muffler to be in communication with each other. Accordingly, a backflow of a compressed refrigerant is prevented during the operation of the compressor, and thus over-compression of the refrigerant can be prevented. Also, when the compressor stops operating, only a certain amount of the discharged refrigerant is allowed to flow backward to prevent a reverse rotation of an orbiting scroll and a decrease in the oil level of the oil stored in a case.