A method for manufacturing a disposable worn article, including: severing a continuous web W along a cut-off line L1 having a predetermined wave shape, dividing the continuous web W into a first and second divided webs W1, W2; allowing the first and second divided webs W1, W2 to cross each other in a width direction X so as to reverse positions of the first and second divided webs W1, W2 in the width direction X; reversing the second divided web W2 by twisting the second divided web W2 by 180°; rotating a second side panel which is cut off from the second divided web W2 by 180°, thereby producing a second side panel PR in line symmetry with a first side panel PL which is cut off from the first divided web W1; and placing and fastening the side panels PL, PR to the side portions of the body 20.