A distributor (101, 102) configured to distribute refrigerant to each of a plurality of heat transfer tubes extending in an up-down direction, the plurality of heat transfer tubes being spaced apart from each other in a first direction crossing the up-down direction, the distributor comprising: a first member having a plurality of first through holes spaced apart from each other in the first direction; a second member having a first groove facing each of the plurality of first through holes; and a third member having at least one second groove provided to face at least one of the plurality of first through holes, wherein the first groove extends in the first direction, a first space inside the first groove and a second space inside the at least one second groove are connected to each other through a third space inside each of the plurality of first through holes, characterised in that an inner diameter of the at least one second groove in the second direction is longer than the length of the opening end of the first groove in the second direction, the distributor (101, 102) further comprises an outer member having an upper surface (101A, 102A) of the distributor (101, 102), the outer member being disposed above the third member and facing at least a part of the at least one second groove, wherein the upper surface (101A, 102A) of the outer member is provided with a plurality of third through holes facing the at least one second groove, the plurality of third through holes being spaced apart from each other in the first direction, and each of the plurality of third through holes has a long-side direction extending in the second direction, the distributor further comprises a fifth member, the fifth member is provided with a plurality of fifth through holes spaced apart from each other in the first direction, the at least one second groove is provided in the third member as a second through hole facing each of the plurality of first through holes and each of the plurality of fifth through holes, an inner diameter of each of the plurality of third through holes in the second direction is longer than a length of each of the plurality of heat transfer tubes in the second direction, an inner diameter of each of the plurality of fifth through holes in the second direction is shorter than a length of each of the plurality of heat transfer tubes in the second direction, each of the first member, the second member, the third member, and the fifth member is formed of a plate-shaped member, and the outer member is configured to caulk at least the first member, the third member and the fifth member that are stacked. a first member having a plurality of first through holes spaced apart from each other in the first direction; a second member having a first groove facing each of the plurality of first through holes; and a third member having at least one second groove provided to face at least one of the plurality of first through holes, wherein the first groove extends in the first direction, a first space inside the first groove and a second space inside the at least one second groove are connected to each other through a third space inside each of the plurality of first through holes, characterised in that an inner diameter of the at least one second groove in the second direction is longer than the length of the opening end of the first groove in the second direction, the distributor (101, 102) further comprises an outer member having an upper surface (101A, 102A) of the distributor (101, 102), the outer member being disposed above the third member and facing at least a part of the at least one second groove, wherein the upper surface (101A, 102A) of the outer member is provided with a plurality of third through holes facing the at least one second groove, the plurality of third through holes being spaced apart from each other in the first direction, and each of the plurality of third through holes has a long-side direction extending in the second direction, the distributor further comprises a fifth member, the fifth member is provided with a plurality of fifth through holes spaced apart from each other in the first direction, the at least one second groove is provided in the third member as a second through hole facing each of the plurality of first through holes and each of the plurality of fifth through holes, an inner diameter of each of the plurality of third through holes in the second direction is longer than a length of each of the plurality of heat transfer tubes in the second direction, an inner diameter of each of the plurality of fifth through holes in the second direction is shorter than a length of each of the plurality of heat transfer tubes in the second direction, each of the first member, the second member, the third member, and the fifth member is formed of a plate-shaped member, and the outer member is configured to caulk at least the first member, the third member and the fifth member that are stacked.