A hot water supply apparatus using a heat medium provides a heat medium circulation path that circulates the heat medium, a heat medium pump that pumps the heat medium into the heat medium circulation path, a heat source that generates heat heating the heat medium, a heat medium heat exchanger that exchanges heat generated by the heat source for the heat medium, a hot water supply heat exchanger that exchanges heat of the heat medium circulating in the heat medium circulation path for clean water, and a control unit that sets the heat medium in the heat medium circulation path in a predetermined temperature and controls the rotating speed of the heat medium pump and the combustion amount of the heat source according to a heat requirement.