To reduce the number of parts of the refrigerant tank and to reduce the number of assembling steps.

An accumulator 1 includes a header 4 having a bottomed cylindrical body 3 and a refrigerant inlet 8 and a refrigerant outlet 9 and sealing an opening end of the body 3, a cylindrical concave part 15 for separating the refrigerant flowing in from the refrigerant inlet 8 to liquid refrigerant and gas refrigerant and oil, an outer pipe 5 and the inner pipe 6 connected to the refrigerant outlet 9 and guiding the gas refrigerant separated by the cylindrical concave part 15 to the refrigerant outlet 9, and an oil returning hole 24 arranged in the bottom of the outer pipe 5 and guiding the oil accumulated in the bottom of the body 3 into the inner pipe 6, and a strainer 20 arranged between the cylindrical concave part 15 and the oil returning hole 24 and removing the foreign matter contained in the liquid refrigerant and the oil, the strainer 20 is formed integrally with the outer pipe 5.