A solar battery module as a panel-shaped semiconductor module comprises multiple rod-shaped electric power generation semiconductor elements arranged in multiple rows and columns, a conductive connection mechanism connecting in series multiple semiconductor elements in each column and electrically connecting in parallel multiple semiconductor elements in each row, and a conductive inner metal case housing the multiple semiconductor elements and constituting the conductive connection mechanism, wherein each row of semiconductor elements is housed in each reflecting surface-forming groove of the inner metal case, the positive electrodes of the semiconductor electrodes are connected to the bottom plate and the negative electrodes are connected to finger leads, and the top is covered with a transparent cover member.