To solve the problem that a position regulating member is joined with an endless belt in an elongated state.

The device is equipped with at least two belt winding rollers 15 and 16 which form a work area Zw for joining the position regulating member 13 with the endless belt 11, a belt rotating means which rotates the endless belt 11 wound around the belt winding rollers 15 and 16, a joining roller 33 for joining the position regulating member 13 with a specific position of the endless belt 11, a backup roller 34 which faces the joining roller 33 across the endless belt 11 and position regulating member 13 and receives a pressing force from the joining roller 33, a guide member 36 having a formed guide groove 35 for guiding the position regulating member 13 to the side of the joining roller 33, a plurality of air blowout holes which are bored in the guide groove 35 and spout air respectively, and member supply rollers 37 and 38 which supply the position regulating member 13 toward the joining roller 33 along the guide groove 35.