The present invention of a contactless electric power supply device comprises a contactless electric power supply element provided on a fixed section, a high-frequency power source circuit for supplying high frequency power to the contactless electric power supply element, a contactless electric power reception element for receiving high frequency electric power in a contactless manner which is facing and separated from the contactless electric power supply element and which is provided on the movable section, an electric power reception circuit which supplies electric power to the current consumer on the movable section after converting the high-frequency power which the contactless electric power reception element received; wherein the contactless electric power reception element has a heat radiating layer or heat radiating surface which radiates the heat generated by the current consumer with high emissivity, the contactless electric power supply element has a heat absorbing layer or heat absorbing surface which absorbs heat with a high absorption rate, such that the some of the heat generated by the current consumer is transferred from the contactless electric power reception element to the contactless electric power supply element and then diffused at the fixed section side. And from this, the cooling ability of the movable section is improved and the movable section can be more compact and lightweight.