A refrigeration / air-conditioning device comprising: a refrigeration cycle in which at least a compressor, a heat source-side heat exchanger, an electronic expansion valve (9,11), and a utilization-side heat exchanger are connected via refrigerant piping and which is filled with a refrigerant whose discharge temperature Td increases more easily than that of an R410A refrigerant; a discharge temperature sensor and a suction temperature sensor; and an expansion valve control means which controls an aperture of the electronic expansion valve (9,11) at a predetermined degree of suction gas superheat SH when the discharge temperature Td is not more than an upper-limit value and controls the aperture of the electronic expansion valve (9,11) at a predetermined degree of discharge superheat TdSH or a predetermined discharge temperature Td when the discharge temperature Td exceeds the upper-limit value, characterized in that the expansion valve control means comprises a target value switching means which switches, when the expansion valve control means is performing the control at the predetermined degree of discharge superheat TdSH while controlling the aperture of the expansion valve (9,11) at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, the control at the predetermined degree of discharge superheat TdSH to the control at the predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td using, as a target value, the lower one of an upper-limit value of the discharge temperature Td and a target degree of discharge superheat TdSH obtained by calculation from the rotational speed of the compressor and a high pressure saturation temperature, and compares, when the expansion valve control means is performing the control at the predetermined discharge temperature Td, a target discharge temperature Td obtained by calculation from the rotational speed of the compressor and the high pressure saturation temperature with the upper-limit value and adopts the lower one of the target discharge temperature Td and the upper-limit value as the target discharge temperature Td. a refrigeration cycle in which at least a compressor, a heat source-side heat exchanger, an electronic expansion valve (9,11), and a utilization-side heat exchanger are connected via refrigerant piping and which is filled with a refrigerant whose discharge temperature Td increases more easily than that of an R410A refrigerant; a discharge temperature sensor and a suction temperature sensor; and an expansion valve control means which controls an aperture of the electronic expansion valve (9,11) at a predetermined degree of suction gas superheat SH when the discharge temperature Td is not more than an upper-limit value and controls the aperture of the electronic expansion valve (9,11) at a predetermined degree of discharge superheat TdSH or a predetermined discharge temperature Td when the discharge temperature Td exceeds the upper-limit value, characterized in that the expansion valve control means comprises a target value switching means which switches, when the expansion valve control means is performing the control at the predetermined degree of discharge superheat TdSH while controlling the aperture of the expansion valve (9,11) at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, the control at the predetermined degree of discharge superheat TdSH to the control at the predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td using, as a target value, the lower one of an upper-limit value of the discharge temperature Td and a target degree of discharge superheat TdSH obtained by calculation from the rotational speed of the compressor and a high pressure saturation temperature, and compares, when the expansion valve control means is performing the control at the predetermined discharge temperature Td, a target discharge temperature Td obtained by calculation from the rotational speed of the compressor and the high pressure saturation temperature with the upper-limit value and adopts the lower one of the target discharge temperature Td and the upper-limit value as the target discharge temperature Td.