A heat radiation structure (10) includes a casing (4) configured to accommodate a heating element (1), and a heat-sink type component (2) configured to directly or indirectly absorb heat from the heating element (1), contactlessly face the casing (4), and conduct the heat to the casing (4) via air existing in an internal space of the casing (4), wherein at least either the heat-sink type component (2) or the casing (4) is configured in such a way that, when heat is generated from the heating element (1), a distance between the heat-sink type component (2) and the casing (4) becomes nearer in a region of the internal space (3) in which temperature does not rise relatively easily than in a region of the internal space (3) in which temperature rises relatively easily.