A power supply for supplying electric power to a device includes a power generation module. The module includes a power generation portion for generating power by using supplied power generation fuel, a fuel pack accommodating section which can accommodate a plurality of fuel packs capable of storing the power generation fuel, and from which the plurality of fuel packs can be independently removed, and a control portion which performs control such that, while the power generation fuel is supplied from one of the plurality of fuel packs accommodated in the fuel pack accommodating section, the power generation fuel is not supplied from another fuel pack of the plurality of fuel packs.