Heat generating device and method for generating heat

A heat generating device comprising:

• a container into which a hydrogen-based gas contributing to heat generation is configured to be introduced;
• a heat generating element provided inside the container;
• a heater configured to heat the heat generating element;
• and
• a pump, 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 a surface of the base, the multilayer film having a stacking configuration of:
• a first layer that is made of a hydrogen storage metal or a hydrogen storage alloy and has a layer shape with a thickness of less than 1000 nm;
• and
• a second layer that is made of a hydrogen storage metal, a hydrogen storage alloy, or ceramics different from that of the first layer and has a layer shape with a thickness of less than 1000 nm, wherein
• the base has a porous structure or a mesh structure, and includes a hollow surrounded by an inner peripheral surface of the base, and
• the pump is configured to guide the hydrogen-based gas in the container into the hollow by allowing the hydrogen-based gas to permeate sequentially through the multilayer film and the base.