To provide a heat exchanging device not needing a driving source excluding temperature difference.

This heat exchanging device comprises a first heat exchange portion 11 and a second heat exchange portion 12 respectively disposed in different temperature environments, a first circulation passage 14 and a second circulation passage 15 composed of a material of high heat insulating property and connecting the first and second heat exchange portions 11, 12, and a liquid used as a heat transmitting medium by being circulated in the first heat exchange portion and the second heat exchange portion through the first and second circulation passages 14, 15. As the heat exchange portions are disposed with difference in height, the heat exchange is performed by circulating the liquid by natural convection of the liquid by temperature difference in accompany with the heat exchange, thus the driving force excluding the temperature difference is unnecessary.