To provide a printer capable of detecting a terminal end of paper or an ink sheet without using paper or an in sheet in which processing for terminal end detection is performed, and without applying tension on the paper or the ink sheet.

A printer of this invention is a printer which transfers a color material of an ink sheet 2 to paper 6 and performs printing. The printer at least includes either a paper bobbin 13 around which the paper 6 is wound and which is attachable to/detachable from the printer, or an ink bobbin (that is, an ink bobbin 8 on a supply side) around which the ink sheet 2 is wound and which is attachable to/detachable from the printer. On the surface of a shaft part of the paper bobbin 13 and/or the ink bobbin, groove-shaped 13a and 8a are formed. The printer also includes a groove shape detection means which detects the groove-shaped 13a and 8a.