The present technology relates to a semiconductor device and a solid-state imaging device of which crack resistance can be improved in a simpler way. The semiconductor device has an upper substrate that is constituted by a Si substrate and wiring layers laminated on the Si substrate and a second substrate that is constituted by a Si substrate and wiring layers laminated on the Si substrate and is joined to the upper substrate. In addition, a pad for wire bonding or probing is formed in the upper substrate, and pads for protecting corner or side parts of the pad for wire bonding or probing are radially laminated and provided in each of the wiring layers between the pad and the Si substrate of the lower substrate. The present technology can be applied to a solid-state imaging device.