PURPOSE: To prevent such a simple trouble as not capable of performing operation because of shortage of the residual sheet amount by storing in memory the radius of roll paper corresponding to the revolving amount of a roll paper supporting means and the residual sheet amount corresponding to each radius, and sensing the current sheet residual amount from the revolving speed of this roll paper supporting means.

CONSTITUTION: In an automatic drawing machine or the like in which the roll part of roll paper 16 is borne rotatably by a supply side roll paper supporting means 10 and in which the roll paper 16 is fed to over the working surface, the radii of roll paper 16 corresponding to the revolving amount of the mentioned supporting means 10 from a plurality of initial radii of roll paper 16 and the residual sheet amount corresponding to each radii are tabulated and stored in a memory device. The roll paper 16 which has been in the initial radius condition is fed toward the working surface, and the current radius of roll paper 16 is determined from the revolving amount of the roll paper supporting means 10 at this time by reference to the table, and thus the residual sheet amount corresponding to the radius is sensed.