A cooling device 100 includes a first heat receiving unit 400, a second heat receiving unit 410, a first heat dissipating unit 700, and a second heat dissipating unit 710. The first heat dissipating unit 700 and the second heat dissipating unit 710 have a flat plate shape and have a structure in which air passes in a direction approximately perpendicular to a principal surface having a flat plate shape and a first principal surface 730 that is a principal surface having a flat plate shape in the first heat dissipating unit 700 and a second principal surface 740 that is a principal surface having a flat plate shape in the second heat dissipating unit 710 are arranged so as to face to each other. As a result, the size of the cooling device 100 can be reduced without degrading a heat dissipation performance to dissipate heat generated by a heat generating element.