A heat exchanger comprising: a distributor comprising a fluid inlet (12a_1) and a plurality of fluid outlets (112B, 14a_2), the distributor including a distribution flow passage configured to cause the fluid inlet (12a_1) to communicate with the fluid outlets (112B, 14a_2), and distribute fluid which flows into the distribution flow passage through the fluid inlet (12a_1), among the fluid outlets (112B, 14a_2); and the heat exchanger comprising a plurality of heat transfer tubes into which the fluid flows after flowing out through the fluid outlets of the distributor, the distributor including a plurality of heat-transfer-tube insertion portions each formed to face an associated one of the fluid outlets (112B, 14a_2), the heat-transfer-tube insertion portions allowing heat transfer tubes to be inserted therein, the heat transfer tubes being inserted in the heat-transfer-tube insertion portions such that a distal end portion of each of the heat transfer tubes is connected to the associated fluid outlet (112B, 14a_2), wherein the fluid inlet(12a_1), the distribution flow passage, the fluid outlets (112b, 14a_2) and the heat transfer tube insertion portions are provided by stacking a plurality of plate-shaped bodies (12_1, 13_1, 12_2, 13_2, 12_3, 13_3, 12_4, 14, 15) including through holes (12a_1, 12_a2, 12a_3, 12a_4, 13a_1, 13a_2, 13a_3, 14a_1, 14a_2, 15a_1, 15_a2) formed therein, the downstream outermost through-holes (12a_3) at an end side of the distribution flow passage being each provided in one of said plate-shaped bodies (12_3), characterized in that the downstream outermost through-holes (12a_3) have a flow-passage cross section formed in the shape of a combination of a Z-shaped portion which is a Z-shaped portion of the flow-passage cross section and two linear portions parallel to each other and which are continuous with the Z-shaped portion at both ends thereof, the linear portions, which correspond to the fluid outlets, being formed as an opening portion having a larger area than an area of the distal end portion of each of the heat transfer tubes. a distributor comprising a fluid inlet (12a_1) and a plurality of fluid outlets (112B, 14a_2), the distributor including a distribution flow passage configured to cause the fluid inlet (12a_1) to communicate with the fluid outlets (112B, 14a_2), and distribute fluid which flows into the distribution flow passage through the fluid inlet (12a_1), among the fluid outlets (112B, 14a_2); and the heat exchanger comprising a plurality of heat transfer tubes into which the fluid flows after flowing out through the fluid outlets of the distributor, the distributor including a plurality of heat-transfer-tube insertion portions each formed to face an associated one of the fluid outlets (112B, 14a_2), the heat-transfer-tube insertion portions allowing heat transfer tubes to be inserted therein, the heat transfer tubes being inserted in the heat-transfer-tube insertion portions such that a distal end portion of each of the heat transfer tubes is connected to the associated fluid outlet (112B, 14a_2), wherein the fluid inlet(12a_1), the distribution flow passage, the fluid outlets (112b, 14a_2) and the heat transfer tube insertion portions are provided by stacking a plurality of plate-shaped bodies (12_1, 13_1, 12_2, 13_2, 12_3, 13_3, 12_4, 14, 15) including through holes (12a_1, 12_a2, 12a_3, 12a_4, 13a_1, 13a_2, 13a_3, 14a_1, 14a_2, 15a_1, 15_a2) formed therein, the downstream outermost through-holes (12a_3) at an end side of the distribution flow passage being each provided in one of said plate-shaped bodies (12_3), characterized in that the downstream outermost through-holes (12a_3) have a flow-passage cross section formed in the shape of a combination of a Z-shaped portion which is a Z-shaped portion of the flow-passage cross section and two linear portions parallel to each other and which are continuous with the Z-shaped portion at both ends thereof, the linear portions, which correspond to the fluid outlets, being formed as an opening portion having a larger area than an area of the distal end portion of each of the heat transfer tubes.