To provide a swing-type accumulator that does not require a pipeline connection space on a side with a simple structure and at low costs.

The accumulator includes a tank body 2 comprising a cylindrical shell 3 whose upper end is opened, and a header 4 coupled to an opening of the shell. The header is provided with a refrigerant flow-in hole 8 and a refrigerant flow-out hole 9 opened in a vertical direction. An inner pipe 6 is coupled with the refrigerant flow-out hole, and an outer pipe 5 is arranged outside the inner pipe to form a double pipe. An introduction pipe 30 for emitting a refrigerant flowing in the vertical direction therefrom as a swirl flow in a direction along an inner periphery of the shell is coupled with the refrigerant flow-in hole. An emission port of the introduction pipe is positioned below an upper end of the outer pipe. An upper end 5a of the outer pipe is enlarged into a trumpet-like shape, and a trumpet-shaped part 5b may extend into contact with the inner periphery of the shell. Upper and lower parts of the trumpet-shaped part are communicated via an opening 5c formed at one part of the trumpet-shaped part.