Abstract: A perforator of enhanced performance is disclosed which comprises a punch and a perforation jig comprising upper and lower oblong sheet retainer plates adapted to hold paper sheets, so that in the course of perforation, the perforation jig will retain the punch fast in position with respect to the paper sheets and prevent the punch from being shaken in the vertical direction relative to the perforation jig. The perforator of this invention is constructed so that when the front portion of the punch is abutted against the upper sheet retainer plate forming part of the perforation jig, a punch-supporting member of the lower sheet retainer plate protruding outwardly from the upper sheet retainer plate advances into a recess extended from the front side to the rear side of the punch adapted to receive insertion of paper sheets and, consequently, the perforation jig is allowed to hold the punch safely.