A refrigeration apparatus comprising: a refrigerant circuit in which a heat source-side unit and a utilization-side unit are connected together through a liquid-side connection pipe and a gas-side connection pipe and a main controller including a liquid hammer avoidance control section, the refrigeration apparatus allowing a refrigerant to circulate through the refrigerant circuit to perform a refrigeration cycle, wherein the heat source-side unit includes a compressor (31a-31c), a heat source-side heat exchanger, and a heat source-side expansion valve provided for a pipe sending the refrigerant condensed in the heat source-side heat exchanger to the liquid-side connection pipe, the utilization-side unit includes a utilization-side heat exchanger, a utilization-side expansion valve, and a utilization-side solenoid valve, which are arranged in series, the utilization-side unit further comprising a utilization-side controller and being switchable between a cooling state where the utilization-side solenoid valve opens to allow the utilization-side heat exchanger to function as an evaporator, and a suspended state where the utilization-side solenoid valve is closed to block the refrigerant from flowing through the utilization-side heat exchanger, and characterised in that when the utilization-side unit is switched from the cooling state to the suspended state, the utilization-side controller of the utilization-side unit is configured to output a thermo-off signal, to the main controller, indicating that the utilization-side unit has been suspended, the liquid hammer avoidance control section being configured to receive the thermo-off signal from the utilization-side controller and to output a valve open command to the utilization-side controller to keep the utilization-side solenoid valve open and to fully close the heat source-side expansion valve and then stop the compressor (31a - 31c), and the liquid hammer avoidance control section is configured to then cancel the valve open command, wherein the utilization-side controller of the utilization-side unit is configured to close the utilization-side solenoid valve. a refrigerant circuit in which a heat source-side unit and a utilization-side unit are connected together through a liquid-side connection pipe and a gas-side connection pipe and a main controller including a liquid hammer avoidance control section, the refrigeration apparatus allowing a refrigerant to circulate through the refrigerant circuit to perform a refrigeration cycle, wherein the heat source-side unit includes a compressor (31a-31c), a heat source-side heat exchanger, and a heat source-side expansion valve provided for a pipe sending the refrigerant condensed in the heat source-side heat exchanger to the liquid-side connection pipe, the utilization-side unit includes a utilization-side heat exchanger, a utilization-side expansion valve, and a utilization-side solenoid valve, which are arranged in series, the utilization-side unit further comprising a utilization-side controller and being switchable between a cooling state where the utilization-side solenoid valve opens to allow the utilization-side heat exchanger to function as an evaporator, and a suspended state where the utilization-side solenoid valve is closed to block the refrigerant from flowing through the utilization-side heat exchanger, and characterised in that when the utilization-side unit is switched from the cooling state to the suspended state, the utilization-side controller of the utilization-side unit is configured to output a thermo-off signal, to the main controller, indicating that the utilization-side unit has been suspended, the liquid hammer avoidance control section being configured to receive the thermo-off signal from the utilization-side controller and to output a valve open command to the utilization-side controller to keep the utilization-side solenoid valve open and to fully close the heat source-side expansion valve and then stop the compressor (31a - 31c), and the liquid hammer avoidance control section is configured to then cancel the valve open command, wherein the utilization-side controller of the utilization-side unit is configured to close the utilization-side solenoid valve.