Abstract: Disclosed is a printer apparatus for correcting a slant of a medium at a medium insertion port. This printer apparatus corrects slants of the mediums having a variety of thicknesses. The printer apparatus comprises a slant correcting mechanism for correcting the slant of the medium inserted, a conveying roller for conveying the medium the slant of which is corrected, and a printing mechanism for executing a print on the medium conveyed by the conveying roller. This slant correcting mechanism includes a plurality of polygonal rollers, having rotational phases different from each other, for conveying the medium, and an impingement member upon which the medium conveyed by the polygonal rollers impinges.