Manufacturing method of semiconductor device and semiconductor device

In a dividing method according to the present invention, a wiring board formed of ceramic is forced up (upper swing) by a lower clamp claw of a clamper, and some of a protruded wiring board portion protruding from a conveying chute is pressed against a support body to perform a first division under bending stress. Thereafter, the upward-located clamper is rotatably swung (lower swing) downward to allow an upper clamp claw to press down the protruded wiring board portion, thereby performing a reverse division at the first division section again as a second division. Since the second division allows a tensile force to act on a remaining and thin non-divided resin portion, the non-divided resin portion is torn off. Thus, the perfect division is enabled. Fractionalizing is done by a one-row division and an individual division so that each semiconductor device is formed.