A blanket/plate mounting apparatus includes a leading edge holding unit, trailing edge holding unit, and first drive unit. The leading edge holding unit is movably supported by a cylinder and holds the leading edge of a blanket/plate. The trailing edge holding unit is movably supported by the cylinder and holds the trailing edge of the blanket/plate. The first drive unit moves the leading edge holding unit and the trailing edge holding unit that respectively hold the leading edge and trailing edge of the blanket/plate mounted on the circumferential surface of the cylinder, thus tightening the blanket/plate.