To suppress a circumferential speed difference between a stitching roll and a rotating top tread generated when stitching is applied to the top tread.

The stitching device performs bonding by pressing a top tread 10 being a tire constituent member to a green case 12 deformed in a rotating toroidal shape. The stitching device includes a plurality of rotatable divided rolls 20(1)-20(4) of a truncated cone shape having respective different diameters. The divided rolls 20 are mounted on a roll shaft 25 in a manner freely rotatable in order of the diameter dimensions thereof so as to form the truncated cone as a whole. When a slope 10(2)a of the circumferential edge of the rotating top tread 10 is pressed, each divided roll 20 is rotated in a manner individually following the slope 10(2)a.