Provided is a heat exchanger, including: a refrigerant distributor including: a gas-liquid separating portion having a function of separating a gas-liquid refrigerant mixture into a liquid refrigerant and a gas refrigerant; and a distributing portion provided to the gas-liquid separating portion. A plurality of heat transfer pipes connected to the distributing portion. The plurality of heat transfer pipes are arranged side by side in a first direction, and extend along a second direction intersecting with the first direction. When the refrigerant distributor is viewed along a direction orthogonal to each of the first direction and the second direction, a first space forming portion overlaps a region of the plurality of heat transfer pipes. When the refrigerant distributor and the heat transfer pipes are viewed along the first direction, a clearance is present between the gas-liquid separating portion and the heat transfer pipes.