A refrigerant circuit includes: plural gas/liquid separators adapted to separate a two-phase gas-liquid refrigerant into refrigerant vapor and refrigerant liquid; a channel switching valve connected upstream of the gas/liquid separators and adapted to switch channels for the two-phase gas-liquid refrigerant by opening and closing; an evaporating heat exchanger adapted to accept inflow of the refrigerant liquid or the two-phase gas-liquid refrigerant, the refrigerant liquid produced by separation by the gas/liquid separators; a header installed upstream of the evaporating heat exchanger perpendicularly or at angles to the evaporating heat exchanger; a compressor installed downstream of the evaporating heat exchanger; and plural bypass routes connected to the respective gas/liquid separators and adapted to allow passage of the refrigerant vapor. The refrigerant vapor passing through the plural bypass routes and refrigerant vapor passing through the evaporating heat exchanger merge at a first meeting point between the evaporating heat exchanger and the compressor.