To provide a self-adhering tape cutoff device which draws out and cuts a self-adhering tape, thereby automatically turning back a distal part of the self-adhering tape to form a tongue-like non-adhesive face easily and certainly.

In a self-adhering tape cutoff device which includes: a first tape holding face formed to temporarily stick and hold the self-adhering tape to an end of a self-adhering tape roll backing 3; and a second tape holding member which is altogether provided with a second tape holding face for temporarily sticking and holding the self-adhering tape similarly, and a cutoff device for cutting the self-adhering tape, and is held to move swingably, in turn in a direction of drawing out a self-adhering tape 13, applies tensile force to the self-adhering tape roll backing via the self-adhering tape, moves the self-adhering tape roll backing, and also moves the adjacent second tape holding member relatively to move to a separate position in which the first tape holding face and the second tape holding face are set, the self-adhering tape roll backing is swingably held in the vicinity of the first tape holding face.