To simply cut and form selectively one of an overlap width having a glue flap at one side edge of the corrugated board and an overlap width having no glue flap without moving the position of the first stitch margin base of first and second arcuate blades.

In this end part cutting device for a corrugated board, arcuate blades 31 and 32 provided in a given position with two inclination blades 31d, 31e, 32d, and 32e are attached to a single upper blade holder. This constitution forms both a trapezoidal overlap width and an overlap width, by which a glue flap is longitudinally extended, only by changing the mounting position of the first and second arcuate blades 31 and 32 to an upper blade holder 1.