To reduce the size and assembling labor of an outdoor unit while shortening the assembling time by disposing a compressor for compressing refrigerant and an accumulator for supplying refrigerant to the compressor while integrating vertically thereby reducing the installation area.

The outer shell 134 of a compression unit 130 is partitioned vertically by a barrier wall 135 into independent spaces, i.e., an upper space serving as a compression mechanism section 130a and a lower section serving as an accumulator mechanism section 150. At the upper part of the accumulator 150, a refrigerant suction pipe 152 is provided in the circumferential direction of the outer shell 134 so that refrigerant from an evaporator turns along the inner circumference of the shell 134. The accumulator 150 and a compressor 130a are interconnected through an interconnecting pipe 179 and a refrigerant outlet pipe 153 constituting a part of the interconnecting pipe is provided on the accumulator side. The refrigerant outlet pipe is provided with oil return holes 153b at the open pipe end 153a and in the side face thereof. The work for building in the accumulator independently is thereby eliminated.