PURPOSE: To uniformize tensile force of a web fed from a web roll and tensile force of a web delivered at a delivery part by eliminating their difference.

CONSTITUTION: In accordance with detection of diameter of a web roll 1, rotating speed of a support shaft 2 is controlled so that feeding length of a web 1a from the web roll 1 matches delivery length of the web la of a delivery part 4 at the time. Consequently, as diameter of the web roll 1 comes to be smaller, the rotating speed of the support shaft 2 is gradually increased and the feeding length of the web 1a from the web roll 1 is increased so as to match the delivery length of the web 1a of the delivery part 4 at the time, and simultaneously, at the time when working speed of the delivery part 4 and/or the delivery length of the web 1a changes, by changing the rotating speed of the support shaft 2 in the same way following it, the feeding length of the web 1a from the web roll 1 and the delivery length of the web 1a of the delivery part 4 always match each other.