There is disclosed a method of controlling a web feeding device comprising a pair of center blocks disposed upon predetermined movable members so as to oppose each other with their axes being aligned so as to perform loading and unloading of a web roll by moving closer to or farther away from each other, a lifter disposed adjacent to the movable members and vertically driven so as to elevate the web roll loaded thereon, and a sensor which detects alignment of the pair of center blocks with the core tube of the web roll; wherein:the pair of center blocks are stopped at a predetermined position, prior to the ascending stroke of the lifter, by moving said movable members;the lifter having the web roll loaded thereon is ascended; andthe alignment of the core tube of the web roll with the pair of center blocks is detected by the sensor so as to instantaneously stop the ascending motion of the lifter.