Heat generation device, heat utilization system and film-like heat generation element

A heat generating device comprising:

• a hollow sealed container;
• a tubular body provided in a hollow portion formed by an inner surface of the sealed container;
• a heat generating element provided on an outer surface of the tubular body and configured to generate heat by occluding and discharging hydrogen contained in a hydrogen-based gas supplied to the hollow portion;
• and
• a flow path formed by an inner surface of the tubular body and through which configured to allow a fluid that exchanges heat with the heat generating element to flow,
• wherein
• the heat generating element includes a base made of a hydrogen storage metal, a hydrogen storage alloy, or a proton conductor, and a multilayer film provided on the base;
• and
• the multilayer film has a first layer made of a hydrogen storage metal or a hydrogen storage alloy and having a thickness of less than 1000 nm, and a second layer made of a hydrogen storage metal or a hydrogen storage alloy, which is different from that of the first layer, or ceramics and having a thickness of less than 1000 nm.