To provide a component supply unit capable of reliably cutting a cover tape and reliably exposing an electronic component when using a new storage tape and supplying the electronic component. A tape processing unit includes a cutter successively cutting a cover tape of a storage tape along a traveling direction following traveling of this storage tape. The cutter includes a blade portion having an angular blade portion so inclined frontwardly downward that a blade is angularly formed, and an upper C-chamfered surface (upper worked surface) which is a flat portion whose width in the horizontal direction gradually narrows from a lower end upwardly to reach the angular blade portion on an upper end formed on a forward end portion of this blade portion.