An apparatus makes plastic bags in succession by intermittently feeding webs of plastic film longitudinally along a path. Movable units are spaced apart along the path and are driven by drive units, one for each movable unit, longitudinally of the film webs. Control switches, one for each movable unit, works on each drive unit to move the corresponding movable unit for position adjustment. The film webs are processed by at least some of the movable units whenever being fed intermittently, to successively make the plastic bags.