INDOOR UNIT OF AIR CONDITIONING APPARATUS

[Object]An indoor unit of an air conditioning apparatus is provided which may detect refrigerant leakage and may inhibit refrigerant in a closed space from becoming a flammability limit concentration or higher in short time when refrigerant leakage occurs.[Solving Means]An indoor unit 10 of an air conditioning apparatus includes a housing 15, a heat exchanger 17 arranged in the housing 15, first refrigerant piping 70 arranged in the housing 15 and passing in the heat exchanger 17, a connection portion 75 connecting the first refrigerant piping 70 with second refrigerant piping 71 routed from an exterior of the housing 15, and a retainment portion 68 as a space accommodating the connection portion 75 and includes a refrigerant leakage detection flow path 80 causing the retainment portion 68 to communicate with a negative pressure space and refrigerant leakage detection means 58 detecting refrigerant flowing through the refrigerant leakage detection flow path 80.