An air-conditioning apparatus includes: a housing having a first space and a second space that are adjacent to each other; a fan provided in the first space and to suck air into the housing; a heat exchanger provided in the first space and cause heat exchange with the air sucked by the fan to be performed; a refrigerant sensor provided in the second space and to detect refrigerant; and a partition plate provided to partition off the first space and the second space and having an air inlet port and an air outlet port.