Abstract: Provided is a compressor, and an oxygen concentrator, that achieve low noise by which the noise does not leak directly to the exterior upon generation of compressed air through suction of raw air, and that allow reducing power consumption of a driving motor. A compressor has a case section; a driving motor provided in the case section and having an output shaft; head sections operated by the rotation of the output shaft of the driving motor and that suck and compress raw air to generate thereby compressed air; a raw air intake section that is provided at the output shaft and that takes in the raw air into the head sections as a result of the rotation of the output shaft and that supplies the raw air towards the head sections; and a pressure regulation section that regulates the pressure within the case section upon suction of the raw air and upon discharge of the generated compressed air.