A semiconductor device has a semiconductor chip having first and second surfaces; a sealing resin formed over the first surface; and a cooling structure having a first conductive layer formed on the first surface, an n-type semiconductor formed on the first conductive layer and having one end thereof being exposed from the sealing resin, a p-type semiconductor formed on the first conductive layer and having one end thereof being exposed from the sealing resin, a second conductive layer contacting the exposed end of the n-type semiconductor, a third conductive layer contacting the exposed end of the p-type semiconductor, a first electrode pad integrally formed with the second conductive layer, a second electrode pad integrally formed with the third conductive layer, and spherical electrodes formed at the first and second electrode pads, respectively.