To lower the number of processes at the time of temporarily assembling a brazing member.

A brazing member 20 for brazing a casing 3 to an upper plate 4 substantially has a disk shape whose outer peripheral edge part bent. The brazing member 20 has a bent part 21 inserted into the inner part of the upper so as to come into contact with the inner wall surface of a tank part and a a plate surface 23 temporarily assembled and disposed on the upper part of the casing 3 so as to come into contact with the upper surface of the casing 3. The brazing member 20 is provided with a bent part 21 for brazing the outer peripheral side of the upper plate 4 to the casing 3 and the plate surface 23 for brazing the inner peripheral side of the plate 4 to the casing 3. Thus, the casing 3 can be brazed to the upper plate 4 by one brazing member 20. Therefore, the number of processes for a temporary assembly can be decreased as compared with a case when a brazing operation has been conventionally carried out by using a plurality of brazing members.