PROBLEM TO BE SOLVED: To achieve the low cost and accurate execution of the adjustment of the slippage of three metering points such the positions of the ends of paper and of a pasting line of the web materials of a corrugator by detecting thereof. SOLUTION: At the execution of the adjustment of the slippages of the positions E 1 and E 2 of the ends of papers of a corrugating medium i and of a liner l and of the position E 3 of the pasting line formed with paste dams 40 and 42 in a single facer, The positions E 1 and E 2 of the ends of papers of the corrugating medium i and the back side liner l 1 and of the position E 3 of the pasting line are picturized in one and the same image with imaging devices 60a and 60b arranged at a position enabling to command a whole view of the corrugating medium i wound about an upper stage roll 12 and the back side liner l 1 at the upstream side from the bonding part between the paste dams 40 and 42 arranged to a paste-spreading roll 34 and the corrugating medium i so as to detect the three metering points E 1 -E 3 through the image processing such as density varying process in order to enable the adjustment of the slippages of the three metering points E 1 -E 3 to inexpensively and accurately be automatized on the basis of their detected values. COPYRIGHT: (C)2011,JPO&INPIT