PURPOSE: To prevent a wrapping film from coming out of a storage box and unwinding and keep this prevention more perfectly.

CONSTITUTION: In an opening of a storage chamber of a storage box, a presser plate having a chevron-shaped edge, in which a width XI in the longitudinally center part of the opening is 87-54% of the width of the opening of the storage chamber, a width X3 in the longitudinally end part of the opening is 44-11% of the width of the opening, and a width X2 in the middle point between the center part and the end part is 70-32% of the width of the opening (where a relation of X1>X2>X3 is should be met), is extended from the edge of a front plate to a storage chamber and disposed at an angle of 92-125 degrees made between the rear surface of the presser plate and the rear surface of the front plate.