To simply prevent a telescope phenomenon of a tape by a packing box.

A packing box 10 includes: a box body 20 with an opened upper end, which is made of a corrugated cardboard, and which houses a tape 90, having a pressure-sensitive adhesive tape material 92 wound around a core material 91, in the state of directing an axial direction of the core material 91 upward and downward; and a top plate 30 which is extended out from an upper end opening edge of the box body 20, which is bent at a plurality of locations midway through extension, which is high enough to close a gap between itself and the tape 90 housed in the box body 20, and which has a presser surface 45 abutting on a top surface of the tape 90 to regulate an ascent of the tape.