A refrigeration apparatus comprising: a refrigerant circuit including a compressor (31, 32, 33), a heat source side heat exchanger, a first utilization side heat exchanger, a second utilization side heat exchanger (81, 91), and a receiver to which a liquid-side end of the heat source side heat exchanger and a liquid-side end of the first utilization side heat exchanger are connected through pipes and through which liquid refrigerant flows into the second utilization side heat exchanger (81,91), and performing a refrigeration cycle, wherein an operation in which refrigerant discharged from the compressor (31, 32, 33) flows into the heat source side heat exchanger and the first utilization side heat exchanger, and dissipates heat, and liquid refrigerant in the receiver flows into the second utilization side heat exchanger (81, 91), and absorbs heat can be performed, the refrigeration apparatus further including a gas vent pipe having one end communicated with a gas space in the receiver and having the other end communicated with a line, which has a lower pressure than an internal pressure of the receiver, of the refrigerant circuit; an on-off valve provided in the gas vent pipe; characterized by a controller for opening the on-off valve based on indicators indicating an amount of refrigerant in the heat source side heat exchanger and an amount of refrigerant in the first utilization side heat exchanger during the operation, and in that: a degree of subcooling of refrigerant at a gas-side end of the heat source side heat exchanger and a degree of subcooling of refrigerant at a gas-side end of the first utilization side heat exchanger, or a degree of subcooling of refrigerant in the heat source side heat exchanger and a degree of subcooling of refrigerant in the first utilization side heat exchanger are used as the indicators indicating the amounts of refrigerant. a refrigerant circuit including a compressor (31, 32, 33), a heat source side heat exchanger, a first utilization side heat exchanger, a second utilization side heat exchanger (81, 91), and a receiver to which a liquid-side end of the heat source side heat exchanger and a liquid-side end of the first utilization side heat exchanger are connected through pipes and through which liquid refrigerant flows into the second utilization side heat exchanger (81,91), and performing a refrigeration cycle, wherein an operation in which refrigerant discharged from the compressor (31, 32, 33) flows into the heat source side heat exchanger and the first utilization side heat exchanger, and dissipates heat, and liquid refrigerant in the receiver flows into the second utilization side heat exchanger (81, 91), and absorbs heat can be performed, the refrigeration apparatus further including a gas vent pipe having one end communicated with a gas space in the receiver and having the other end communicated with a line, which has a lower pressure than an internal pressure of the receiver, of the refrigerant circuit; an on-off valve provided in the gas vent pipe; characterized by a controller for opening the on-off valve based on indicators indicating an amount of refrigerant in the heat source side heat exchanger and an amount of refrigerant in the first utilization side heat exchanger during the operation, and in that: a degree of subcooling of refrigerant at a gas-side end of the heat source side heat exchanger and a degree of subcooling of refrigerant at a gas-side end of the first utilization side heat exchanger, or a degree of subcooling of refrigerant in the heat source side heat exchanger and a degree of subcooling of refrigerant in the first utilization side heat exchanger are used as the indicators indicating the amounts of refrigerant.