A one-time password generator in combination with a conventional creditdebit card comprising a card having a magnetic bar stripe, raised imprint card numbers and name, expiration date and four digit code as are known in the art is provided. There is a conveying device including a belt that holds the print medium, a fan that adsorbs air through suction holes in the belt, and a fan drive controller that drives the suction fan and adjusts power of adsorption of the suction fan. The device is further provided with a retaining plate extending parallel to the pressure plate and movable in the pushing direction.