A refrigerant distributor comprising: an outer pipe through which refrigerant flows and to which a plurality of heat transfer pipes are connected at a predetermined spacing from each other; an inner pipe housed in the outer pipe , through which the refrigerant flows and that has a refrigerant outflow hole through which the refrigerant flows out of the inner pipe into the outer pipe ; and a structural part (C) with which the inner pipe or the outer pipe is provided, in which the refrigerant enters an undeveloped state of two-phase gas-liquid flow, and through which the refrigerant flows into the inner pipe , wherein the refrigerant outflow hole is configured such that an angle between a lower end of the inner pipe on a vertical line passing through a center of the inner pipe and a position of presence of the refrigerant outflow hole as seen from the center of the inner pipe satisfies φ D0 < θ < φ DS , where φ D0 = (-0.0408 × AS + 74.124) × 0.62, φ DS = (-0.0408 × AS + 74.124) × 1.2, φ D0 is a liquid-surface angle of the refrigerant in a case in which it is assumed that a gas-liquid slip ratio of the refrigerant is 1 and a gas-liquid interface of the refrigerant is flat and horizontal, φ DS is a liquid surface angle of the refrigerant, and AS [mm 2 ] is a flow passage cross-sectional area of the inner pipe , characterized in that the inner pipe is further linearly extended than the outer pipe , the structural part (C) is the inner pipe thus extended, and L < 10 × D , where D is an inside diameter of an extended portion of the inner pipe and L is a length of the extended portion of the inner pipe . an outer pipe through which refrigerant flows and to which a plurality of heat transfer pipes are connected at a predetermined spacing from each other; an inner pipe housed in the outer pipe , through which the refrigerant flows and that has a refrigerant outflow hole through which the refrigerant flows out of the inner pipe into the outer pipe ; and a structural part (C) with which the inner pipe or the outer pipe is provided, in which the refrigerant enters an undeveloped state of two-phase gas-liquid flow, and through which the refrigerant flows into the inner pipe , wherein the refrigerant outflow hole is configured such that an angle between a lower end of the inner pipe on a vertical line passing through a center of the inner pipe and a position of presence of the refrigerant outflow hole as seen from the center of the inner pipe satisfies φ D0 < θ < φ DS , where φ D0 = (-0.0408 × AS + 74.124) × 0.62, φ DS = (-0.0408 × AS + 74.124) × 1.2, φ D0 is a liquid-surface angle of the refrigerant in a case in which it is assumed that a gas-liquid slip ratio of the refrigerant is 1 and a gas-liquid interface of the refrigerant is flat and horizontal, φ DS is a liquid surface angle of the refrigerant, and AS [mm 2 ] is a flow passage cross-sectional area of the inner pipe , characterized in that the inner pipe is further linearly extended than the outer pipe , the structural part (C) is the inner pipe thus extended, and L < 10 × D , where D is an inside diameter of an extended portion of the inner pipe and L is a length of the extended portion of the inner pipe . <EOS>