The present invention provides a web butt-joining apparatus, comprising: a turret device that supports an old roll and a new roll on which band-shaped flexible base materials are wound to be capable of being unwound, and is rotatable at every predetermined angle; a cutting drum including a cutting member and a holding device; a cutting and joining drum which includes a cutting receiving member, and a holding device which is capable of rotating at the same speed as conveyance speed of the band-shaped flexible base material at a time of joining the band-shaped flexible base material; and a joining drum which is capable of rotating at the same speed as the conveyance speed of the band-shaped flexible base material at a time of joining the band-shaped flexible base materials, wherein while conveying the band-shaped flexible base material, the web butt-joining apparatus performs cutting and butt-joining of the tail end of the band-shaped flexible base material of the old roll and the tip end of the band-shaped flexible base material of the new roll.