HEATER

PROBLEM TO BE SOLVED: To provide a technology capable of coping with a change of a request at a heating terminal without causing fluctuation in a heating capacity of a heat source machine, relating to a regenerative heater.SOLUTION: A heater which is disclosed by the specification includes a tank for storing a heat medium, a heat source machine for heating the heat medium, a heat storage outward path for sending the heat medium to the heat source machine from the tank, a heat storage homeward path for returning the heat medium to the tank from the heat source machine, a heating terminal for performing heating by radiating the heat of the heat medium, a heating outward path for sending the heat medium to the heating terminal from the tank, a heating homeward path for returning the heat medium to the tank from the heating terminal, a bypass route for sending the heat medium to the heating outward path from the heating homeward path without passing through the tank, and a mixing valve capable of adjusting a ratio between the flow rate of the heat medium that is sent to the tank from the heating homeward path and the flow rate of the heat medium sent to the bypass route from the heating homeward path.