Abstract: A cooler has a simple structure and stably exhibits a good cooling effect, and includes: a working fluid container; and a cooling member provided in the container to be brought into contact with the working fluid and to face a heat generation element. The cooling member has a stacked structure including a first porous body and a second porous body. The first porous body includes: a part supplying the working fluid, by capillary action, to a contact part that is in contact with the heat generation element; and a part discharging vapor generated in the contact part to the second porous body. The second porous body includes: a part supplying the working fluid to the first porous body; and part discharging the vapor discharged from the first porous body, into the working fluid. The second porous body has a higher permeability of the working fluid than the first porous body.