During cooling mode to cool air which constitutes a fluid targeted for heat exchange, a high-pressure coolant having released heat through heat exchange with outside air in an outdoor heat exchanger (14) is shunted to a coolant circuit that inflows to an accumulator (17) constituting a gas/liquid separator; and during heating mode to heat air, low-pressure coolant having been decompressed by a first expansion valve (13) is shunted to a coolant circuit that inflows to the accumulator (17). In so doing, in either operating mode, the temperature differential between the outside air temperature and the temperature of coolant inside the accumulator (17) is reduced, minimizing diminished performance of the refrigeration cycle device due to unnecessary transfer of heat between the coolant inside the accumulator (17) and the outside air.