To enable belt-shaped material to be smoothly delivered while both the end faces of a roll is firmly supported at all times even when the roll is in operation.

This pressing side plate abuts against each end face of a roll comprising wall-mounted belt-shaped material wound up to be put in a pivot supporting the roll thoroughly penetrated at its axial center, each pressing side plate is provided with a boss part 2 through which the pivot can be penetrated, and with each flange part 3 stretched outward from the boss part 2, and the boss part 2 is provided with a lock lever 4 having a lock hole 5 permitting the lever to be engaged with the pivot when the lever is tilted to the direction A around its one end B as a fulcrum, so as to allow its relative movement to be locked, and with a locking spring 6 energizing the lock lever 4 to the tilting direction. In this case, lock is released by letting the lock lever 4 be erected against the energizing force of the locking spring 6 to the direction D opposite to the tilting direction A.