A refrigeration cycle apparatus (1) of the present invention includes: a refrigerant circuit (2); and refrigerant. The refrigerant circuit (2) includes a compressor (4), a condenser (5), an expansion valve (6), an evaporator (7), and an internal heat exchanger (8). The refrigerant is a hydrocarbon refrigerant. The internal heat exchanger (8) includes: an inner pipe (8a); and an outer pipe (8b). The internal heat exchanger (8) is configured to cause heat exchange between the refrigerant flowing inside the inner pipe (8a) in a direction from the condenser (5) toward the expansion valve (6), and the refrigerant flowing inside the outer pipe (8b) and outside the inner pipe (8a) in a direction from the evaporator (7) toward the compressor (4). The refrigerant flowing inside the outer pipe (8b) and outside the inner pipe (8a) is entirely gas.