To provide an compressor with built-in accumulator which can be easily placed even in a narrow space such as an engine compartment of an vehicle, has a closed container which is thin in thickness, and can reduce noise.

This compressor with built-in accumulator has a double structure of an inside closed container 1 and an outside closed container 16, and has a function of accumulator which performs gas-liquid separation of a refrigerant gas at a space S interposed between the inside closed container and the outside closed container. A return pipe 18 is connected to the outside closed container 16. An intake pipe 13 is arranged inside the space S, and an lower end of the intake pipe 13 is connected to an intake port of a first rotary compression part 3a in the inside closed container 1. An oil return pipe 20 is arranged to the intake pipe 13, and opens to an oil reservoir 19 at a bottom part. In a second rotary compression part 3b in the inside closed container 1, a small-sized intake pipe 13a is arranged which takes in the refrigerant gas of an intermediate pressure compressed at the first rotary compression part 3a and delivered in the inside closed container 1, and a delivery pipe 14 for delivering the refrigerant gas compressed to a high pressure is connected.