To provide a compressor and an oxygen concentration device capable of reducing noise without causing the leakage of noise directly to the outside when raw material air is sucked and compressed air is formed, and reducing the electric power consumption of a drive motor.

The compressor 10 includes a case 23, the drive motor 11 disposed in the case 23 and including an output shaft 15, heads 21, 22 operated by the rotation of the output shaft 15 of the drive motor 11 and sucking and compressing the raw material air 70 to form the compressed air 71, a raw material air intake 90 disposed at the output shaft 15 taking the raw material air 70 in by the rotation of the output shaft 15, and supplying the raw material air to the head 21, 22 sides, and a pressure regulating part 250 regulating pressure in the case 23 when the raw material air is sucked and when the generated compressed air is discharged.