PURPOSE: To increase the dehumidifying effect by radiating the heat absorbed on the heat absorbing side of an electronic cooling element with a metallic heat conductive plate in a dehumidifier having the electronic element utilizing the Peltier effect.

CONSTITUTION: An internal case 2, whose upper part 3 is made of metal and whose lower part 4 of a heat insulating material, is arranged in an external case 1, and electronic cooling elements 11a and 11b utilizing the Peltier effect are arranged at the lower part. Heat conductive plates 10a and 10b are arranged vertically in the internal case 2, and jointed to the metallic part 3. In addition, the heating surface of the electronic cooling element is jointed to the lower inner side surface of the heat conductive plates. And cooling fins 12a and 12b are jointed respectively to the cooling surface of the electronic cooling elements and to the upper inner side surface of the heat conductive plates. A heat conductive plate 7 is also furnished at a part of a cooling passage 6 between both cases to conduct the heat of the metallic part 3 of the internal case 2 to the external case 1. The heat radiating effect is consequently increased, and the dehumidifying effect is increased due to the condensation of the moisture in the atmosphere into water by cooling.