An air-conditioning apparatus includes a plurality of indoor units each individually conditioning air in an air-conditioning target space, a storage unit storing detection values of a plurality of suction temperature sensors in time series, a timer measuring, for each of the plurality of indoor units, a preset temperature arrival period it takes for a suction temperature to reach a preset temperature for the air-conditioning target space after start of a thermo-on state or a thermo-off state, a calculation unit calculating, for each of the plurality of indoor units, a temperature change slope representing a change in the suction temperature for the preset temperature arrival period, and a determination unit comparing the temperature change slope of each of the plurality of indoor units with a determination threshold to determine, as an abnormal indoor unit, the indoor unit having the temperature change slope greater than the determination threshold.