Provided is an image forming apparatus that can accurately determine whether a manuscript is pencil writing. The image forming apparatus is a copier with a copy function that, after receiving a copy instruction, reads image data from a manuscript, and prints the read image data on printing paper according to set printing conditions. The copier includes a character extracting unit and a line width judgment unit. The character extracting unit extracts characters from each of a plurality of different locations in image data. The line width judgment unit determines whether or not a manuscript is pencil writing by comparing line widths of the characters that were extracted by the character extracting unit.