An image pickup device including a vacant space portion that allows a connection electrode to be exposed to a second main surface side, the vacant space portion being formed at a position overlapping at least the connection electrode in a state where the image pickup device is viewed in plan view from a thickness direction A, and the connection electrode exposed to the second main surface side is electrically connected with a substrate at a position in the vacant space portion, the position overlapping the image pickup device in the state where the image pickup device is viewed in plan view from the thickness direction.