A web joining device (200) joins a pair of waist sections (10) together while webs (61, 62) for an absorptive article (1) are folded on each other in the intersecting direction (CD) along a folding line which is parallel to the machine direction (MD). The web joining device (200) is provided with an ultrasonic horn (211) which joins the pair of waist sections (10) together, an anvil (222) which faces the ultrasonic horn (211) and sandwiches an intermediate web (6)in cooperation with the ultrasonic horn (211), and a crotch holding bar (240) which, when the intermediate web (6) becomes joined by the ultrasonic horn (211) and the anvil (222), holds the intermediate web (6) with the intermediate web (6) stretched in the direction in which a crotch section (20) is separated from the waist sections.
