Abstract: A cooling device is constructed by a water impermeable member defining a water passage, the water impermeable member being provided with a vapor permeable member which is permeable to water vapor and impermeable to water, and has the form of a mesh and made of a material having water repellency. The cooling device has a long-life operation while preventing wear-out of the vapor permeable member. Further, optimally setting the size of an opening of the mesh member enables to securely dissipate water vapor outside of the cooling device through the vapor permeable member while efficiently suppressing water leak.