A thermal rectifier comprising: a first panel; a second panel arranged to face the first panel; and a switching mechanism provided between the first panel and the second panel and configured to switch, according to respective temperatures of the first panel and the second panel, thermal conductivity between the first panel and the second panel, the switching mechanism including: a first thermally conductive portion thermally connected to the first panel; and a second thermally conductive portion thermally connected to the second panel, at least one of the first thermally conductive portion or the second thermally conductive portion having a property of changing their shape or dimensions as their own temperature varies, the switching mechanism being configured to, as at least one of the first thermally conductive portion or the second thermally conductive portion changes their shape or dimensions, switch from a heat radiation state where the first thermally conductive portion and the second thermally conductive portion are thermally coupled together to a heat insulation state where the first thermally conductive portion and the second thermally conductive portion are thermally isolated from each other, or vice versa, characterised in that the switching mechanism further includes an intermediate panel having thermal conductivity and located between the first thermally conductive portion and the second thermally conductive portion, the heat radiation state is a state where the first thermally conductive portion and the second thermally conductive portion are both thermally connected to the intermediate panel, and the heat insulation state is a state where at least one of the first thermally conductive portion or the second thermally conductive portion is thermally isolated from the intermediate panel. a first panel; a second panel arranged to face the first panel; and a switching mechanism provided between the first panel and the second panel and configured to switch, according to respective temperatures of the first panel and the second panel, thermal conductivity between the first panel and the second panel, the switching mechanism including: a first thermally conductive portion thermally connected to the first panel; and a second thermally conductive portion thermally connected to the second panel, at least one of the first thermally conductive portion or the second thermally conductive portion having a property of changing their shape or dimensions as their own temperature varies, the switching mechanism being configured to, as at least one of the first thermally conductive portion or the second thermally conductive portion changes their shape or dimensions, switch from a heat radiation state where the first thermally conductive portion and the second thermally conductive portion are thermally coupled together to a heat insulation state where the first thermally conductive portion and the second thermally conductive portion are thermally isolated from each other, or vice versa, characterised in that the switching mechanism further includes an intermediate panel having thermal conductivity and located between the first thermally conductive portion and the second thermally conductive portion, the heat radiation state is a state where the first thermally conductive portion and the second thermally conductive portion are both thermally connected to the intermediate panel, and the heat insulation state is a state where at least one of the first thermally conductive portion or the second thermally conductive portion is thermally isolated from the intermediate panel. a first thermally conductive portion thermally connected to the first panel; and a second thermally conductive portion thermally connected to the second panel, at least one of the first thermally conductive portion or the second thermally conductive portion having a property of changing their shape or dimensions as their own temperature varies, the switching mechanism being configured to, as at least one of the first thermally conductive portion or the second thermally conductive portion changes their shape or dimensions, switch from a heat radiation state where the first thermally conductive portion and the second thermally conductive portion are thermally coupled together to a heat insulation state where the first thermally conductive portion and the second thermally conductive portion are thermally isolated from each other, or vice versa, characterised in that the switching mechanism further includes an intermediate panel having thermal conductivity and located between the first thermally conductive portion and the second thermally conductive portion, the heat radiation state is a state where the first thermally conductive portion and the second thermally conductive portion are both thermally connected to the intermediate panel, and the heat insulation state is a state where at least one of the first thermally conductive portion or the second thermally conductive portion is thermally isolated from the intermediate panel.