To provide a roller cutter type cutting equipment for a fiber bundle and a method for cutting a fiber bundle, capable of acquiring staple fibers able to be packed in a good shape even in the case that the staple fibers are minutely crimpled and not easy in opening.

This equipment has (A) a cutter roller which is provided with plural cutter blades 4 on its circumferential surface, (B) a pressing roller for pressing down the cutter roller coiled with a fiber bundle and (C) a funneled auxiliary member 6 for discharging staple fibers, and has at least one nozzle 7 injecting high-pressure air toward the inclined plane of the auxiliary member 6.