PURPOSE: To improve operation efficiency by driving a shifting apparatus by a controller so that the output signals of a pair of sensors are made equal, thus permitting automatic lateral positioning of the paper before and after taking-up operation.

CONSTITUTION: An automatic paper joining feeder is constituted of a paper feeding part 10 and a storage part 11 for storing a web. In the paper feeding part 10, frames 12 and 12 are installed and a turning shaft 13 is laid laterally, and a pair of parallel paper feeding arms 19 and 20 are installed onto the shaft 13. Sensors 59 and 60 are installed at the position symmetrical with respect to the shaft 13, on the inside surface of the arm 19, and connected to converters 61 and 62, and the distance from the side surface of taking-up paper 55, 57 is converted to a comparison signal, which is input into a controller 63. The outputs are compared by a comparator 64 in the apparatus 63, and motors 30 and 34 are revolved normally and reversely through a drive control circuit 65 so that the outputs are made equal, and then a rotary shaft 25 is shifted to adjust the right and the left positions.