An air-conditioning apparatus includes a plurality of indoor units each located inside a building and at a position that enables the indoor unit to condition air, and a relay unit installed in a space not to be air-conditioned inside the building. The relay unit and each indoor unit are connected to each other via a first heat medium pipe in which a first heat medium such as water or brine flows. The relay unit accommodates therein a first refrigerant circuit including a compressor, a plurality of first intermediate heat exchangers that exchange heat between the first heat medium and refrigerant that performs a phase shift or turns to a supercritical state during operation, a plurality of expansion devices, and a second intermediate heat exchanger that exchanges heat between the refrigerant and a second heat medium, which are connected via a refrigerant pipe.