PURPOSE: To improve precision in sending a sensitive material by giving a load to a print medium in a reverse direction with respect to a conveyance direction in accordance with a resistance at the time when the print medium is carried out from its housing.

CONSTITUTION: When a conveyance of a sensitive material 2 is started, a sensitive material pulling force sensing lever 3 moves counterclockwise with center at an axis 6 dependent on the magnitude of an F1. At the same time, control rollers 18 and 19 begin to rotate in the conveyance direction of the sensitive material 2, so that an F4 dependent on the magnitude of the F1 is generated by a frictional force of a friction plate 11 and the control roller 18. If the F1 becomes large when the sensitive material 2 can not be pulled out easily due to some reasons, the sensitive material pulling force sensing lever 3 moves counterclockwise with center at the axis 6, so that a control screw 14 is lowered downward and a downward force with respect to the friction plate 11 becomes large. Accordingly, an F3 becomes small and the frictional force between the friction plate 11 and the control roller 18 is lowered so as to make the F4 small. Next, when the F1 becomes small the sensitive material pulling force sensing lever 3 moves clockwise with center at the axis 6 and the F4 becomes large.