An air conditioner which includes: a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected together in this order, the refrigerant circuit circulating a refrigerant to create a refrigeration cycle; and a switching mechanism connected to the refrigerant circuit, and switching between a heating operation and a defrosting operation, the heating operation causing the refrigerant to condense in the indoor heat exchanger, and the defrosting operation causing the refrigerant to circulate in the opposite direction from the heating operation to defrost the outdoor heat exchanger, the air conditioner comprising a controller configured to carry out a liquid reduction control from the end of the defrosting operation to resumption of the heating operation to which the switching mechanism switches, the liquid reduction control causing the expansion valve to be fully closed or to have an opening degree smaller in the liquid reduction control than in the defrosting operation to reduce an inflow of the liquid refrigerant from the outdoor heat exchanger into the indoor heat exchanger, and characterized in that the refrigerant circuit is filled with R32 as a refrigerant, and in that the controller is configured to carry out the liquid reduction control by performing first and second controls, the first control causing (i) the expansion valve to have the opening degree smaller after the defrosting operation than in the defrosting operation, and (ii) the compressor to have the revolution speed lower after the defrosting operation than in the defrosting operation, and the second control causing (i) the expansion valve to have the opening degree smaller after the first control than in the first control, and (ii) the compressor to stop. a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected together in this order, the refrigerant circuit circulating a refrigerant to create a refrigeration cycle; and a switching mechanism connected to the refrigerant circuit, and switching between a heating operation and a defrosting operation, the heating operation causing the refrigerant to condense in the indoor heat exchanger, and the defrosting operation causing the refrigerant to circulate in the opposite direction from the heating operation to defrost the outdoor heat exchanger, the air conditioner comprising a controller configured to carry out a liquid reduction control from the end of the defrosting operation to resumption of the heating operation to which the switching mechanism switches, the liquid reduction control causing the expansion valve to be fully closed or to have an opening degree smaller in the liquid reduction control than in the defrosting operation to reduce an inflow of the liquid refrigerant from the outdoor heat exchanger into the indoor heat exchanger, and characterized in that the refrigerant circuit is filled with R32 as a refrigerant, and in that the controller is configured to carry out the liquid reduction control by performing first and second controls, the first control causing (i) the expansion valve to have the opening degree smaller after the defrosting operation than in the defrosting operation, and (ii) the compressor to have the revolution speed lower after the defrosting operation than in the defrosting operation, and the second control causing (i) the expansion valve to have the opening degree smaller after the first control than in the first control, and (ii) the compressor to stop.