An air conditioning device, comprising: a main refrigerant circuit having a compressor, an indoor heat exchanger, a main valve, and an outdoor heat exchanger, the main refrigerant circuit being configured to circulate in a heating mode a refrigerant through the compressor, the indoor heat exchanger, the main valve, and the outdoor heat exchanger, in the stated order; a discharge-intake bypass circuit having a superheat valve, the discharge-intake bypass circuit being connected to the main refrigerant circuit so as to bypass, during the heating mode, the refrigerant from a discharge side of the compressor to an intake side of the compressor; and a control unit, wherein the control unit is configured to carry out a positive cycle defrosting mode to defrost the outdoor heat exchanger while circulating refrigerant through the compressor, the indoor heat exchanger, the main valve, and the outdoor heat exchanger in the stated order, and, during the positive cycle defrosting mode, the control unit is configured to carry out a defrosting-mode main valve high-pressure control to open the superheat valve to cause the refrigerant to bypass from the discharge side of the compressor to the intake side of the compressor through the discharge-intake bypass circuit, characterized in that the control unit is configured to carry out the defrosting-mode main valve high-pressure control to adjust a valve opening of the main valve so that a high pressure level in the main refrigerant circuit reaches a target high pressure, the target high pressure being set to a value that is close to an upper limit value of the high pressure level during the heating mode. a main refrigerant circuit having a compressor, an indoor heat exchanger, a main valve, and an outdoor heat exchanger, the main refrigerant circuit being configured to circulate in a heating mode a refrigerant through the compressor, the indoor heat exchanger, the main valve, and the outdoor heat exchanger, in the stated order; a discharge-intake bypass circuit having a superheat valve, the discharge-intake bypass circuit being connected to the main refrigerant circuit so as to bypass, during the heating mode, the refrigerant from a discharge side of the compressor to an intake side of the compressor; and a control unit, wherein the control unit is configured to carry out a positive cycle defrosting mode to defrost the outdoor heat exchanger while circulating refrigerant through the compressor, the indoor heat exchanger, the main valve, and the outdoor heat exchanger in the stated order, and, during the positive cycle defrosting mode, the control unit is configured to carry out a defrosting-mode main valve high-pressure control to open the superheat valve to cause the refrigerant to bypass from the discharge side of the compressor to the intake side of the compressor through the discharge-intake bypass circuit, characterized in that the control unit is configured to carry out the defrosting-mode main valve high-pressure control to adjust a valve opening of the main valve so that a high pressure level in the main refrigerant circuit reaches a target high pressure, the target high pressure being set to a value that is close to an upper limit value of the high pressure level during the heating mode.