According to the method of manufacturing a semiconductor device, a lead frame is provided wherein the thickness of a tab-side end portion of a silver plating for wire connection formed on each suspending lead 1e is smaller than that of a silver plating formed on each lead. An offset circuit calculates an offset of the low-order bit string. The at least one slot also includes a second slot section extending from said second lower surface at least part-way through the die board base. If judged that the attitude is the singular point, angles of the fourth and sixth axes required for the six-axis robot to move to the singular point are determined such that an angle of one of the fourth and sixth axes is fixed to a current value and an angle of the other axis is determined based on the fixed angle. Through movement of the two side components relative to each other, the protective case can be brought into an open state in which the data carrier can be removed from the protective case, characterized in that the data carrier is held against the two side components in an inclined position, so that at least a part of it is accessible from both sides. This arrangement makes it possible to suppress a consuming current and output a bias current that is more stable against a temperature change andor a power supply voltage change.