Abstract: The invention relates to a hydrogen combustion heater. This heater includes (a) a passage for allowing hydrogen gas and air to flow therethrough; (b) a first catalyst provided in the passage, the first catalyst being heated, when electricity is applied thereto, thereby starting a first combustion of a first mixture of the hydrogen gas and the air in the first catalyst; and (c) a heat exchanger provided downstream of the first catalyst in the passage, the heat exchanger being adapted to transfer heat generated by the first combustion to a heating medium of the heat exchanger.