A cooling member includes a fluid-tight sealed body that is formed by a first laminated sheet and a second laminated sheet being joined to each other at at least one joint portion, a coolant that is enclosed in the sealed body, and a heat dissipation plate that is joined in a fluid-tight manner to an inner surface of the sealed body at at least one joint portion and that has a heat absorption portion that is located inside the sealed body and a heat dissipation portion that is located outside the sealed body.