The web conveyor 100 conveys a continuous web 7L for L size and a continuous web 7M for M size. The conveyor 100 includes a guide mechanism 220 changing a passing position of a side edge portion of a web 7, a detection mechanism 230 detecting the passing position of the edge portion of the web 7, and a drive mechanism 240 moving the guide mechanism 220 and the detection mechanism 230 together in the cross direction CD (width direction) of the web 7 according to a size such as L size or M size, by being in contact with a first side edge portion 10A and a second side edge portion 20A of the web 7. The drive mechanism 240 moves the guide mechanism 220 and the detection mechanism 230 by an equal traveling distance in the cross direction CD of the web.
