A heat-accumulating hot-water-supplying air conditioner comprising: - a first circulation channel including a forward route and a return route and configured to connect a first heat demand part which requires hot heat or cold heat, and a first supply heat exchanger which heats or cools a second heat medium through heat exchange with a first heat medium which is temperature increased or temperature decreased, with the forward route along which the second heat medium is directed from the first supply heat exchanger to the first heat demand part, and the return route along which the second heat medium is directed from the first heat demand part to the first supply heat exchanger; - a first heat accumulation tank which is connected to a supply channel and a discharge channel for the second heat medium, the supply channel serving to divide the second heat medium heated by the temperature increased first heat medium in the first supply heat exchanger from the forward route of the first circulation channel, and the discharge channel for the second heat medium joining the return route of the first circulation channel, and which is configured to accommodate the second heat medium heated in the first supply heat exchanger, via the supply channel; - a first switching portion configured to change communication of the second heat medium flowing from the first supply heat exchanger and reaching the first heat demand part and communication of the second heat medium flowing from the forward route of the first circulation channel and branching to the supply channel; characterized in further comprising - a second circulation channel including a forward route and a return route and configured to allow circulation independently of the first circulation channel, and to connect the first heat accumulation tank and a second heat demand part which requires hot heat, with the forward route along which the second heat medium is directed from the first heat accumulation tank to the second heat demand part, and the return route along which the second heat medium is directed from the second heat demand part to the first heat accumulation tank, - wherein the second heat demand part includes: a hot-water-supplying heat exchanger which exchanges heat between the second heat medium circulating in the second circulation channel and water for hot water supply, thereby heating the water. - a first circulation channel including a forward route and a return route and configured to connect a first heat demand part which requires hot heat or cold heat, and a first supply heat exchanger which heats or cools a second heat medium through heat exchange with a first heat medium which is temperature increased or temperature decreased, with the forward route along which the second heat medium is directed from the first supply heat exchanger to the first heat demand part, and the return route along which the second heat medium is directed from the first heat demand part to the first supply heat exchanger; - a first heat accumulation tank which is connected to a supply channel and a discharge channel for the second heat medium, the supply channel serving to divide the second heat medium heated by the temperature increased first heat medium in the first supply heat exchanger from the forward route of the first circulation channel, and the discharge channel for the second heat medium joining the return route of the first circulation channel, and which is configured to accommodate the second heat medium heated in the first supply heat exchanger, via the supply channel; - a first switching portion configured to change communication of the second heat medium flowing from the first supply heat exchanger and reaching the first heat demand part and communication of the second heat medium flowing from the forward route of the first circulation channel and branching to the supply channel; characterized in further comprising - a second circulation channel including a forward route and a return route and configured to allow circulation independently of the first circulation channel, and to connect the first heat accumulation tank and a second heat demand part which requires hot heat, with the forward route along which the second heat medium is directed from the first heat accumulation tank to the second heat demand part, and the return route along which the second heat medium is directed from the second heat demand part to the first heat accumulation tank, - wherein the second heat demand part includes: a hot-water-supplying heat exchanger which exchanges heat between the second heat medium circulating in the second circulation channel and water for hot water supply, thereby heating the water.