An air-conditioning apparatus performs air conditioning by causing heat exchange between refrigerant cycling through a refrigerant circuit and indoor and outdoor air. The air-conditioning apparatus includes a sensor and a control determination device. The sensor measures concentration of any of the refrigerant leaked into the air. The control determination unit determines leakage of the refrigerant in a case when the concentration of any refrigerant leaked into the air is greater than a first threshold. The control determination device further determines an abnormality in the sensor in any one of a case where a cumulative time period of determined leakages is greater than a predetermined time period, a case where a cumulative number of times of determined leakages is greater than a predetermined number, and a case where the value indicating the concentration of any refrigerant leaked into the air is greater than a higher second threshold.