To provide a punching apparatus to be used as a punching/dust collecting system which has an improved cylindrical drill thereby having enhanced cutting efficiency, consequently surely hollows out a core to be cut and prevents the clogging caused by chips and besides has an improved dust collection function thereby having enhanced suction efficiency of chips including cut cores.

A hollow main shaft 12 is used as a main shaft to be rotated by drive sources 10, 20. The cylindrical drill 101 having a blade part 106 at the leading end of a cylinder body is fit to the leading end of the hollow main shaft 12 via a chuck 16. A dust collection mechanism 50 is connected to the back end of a passage 12o in the hollow main shaft 12. A material to be cut is punched while rotating the cylindrical drill through the hollow main shaft by the drive sources, so that the chips to be generated and cut cores are sucked/recovered into the dust collection mechanism 50 through the passage 12o in the hollow main shaft. The cylindrical drill 101 is constituted in such a manner that the shaft center of the cylinder body is made eccentric to the axis of a hole part 103 opened at the leading end of the cylinder body.