A thermal printer having a reciprocating carriage (8), a thermal print head (14) provided on the carriage, a controller (1) for controlling the movement of the carriage and the printing operation of the print head, a ribbon cassette (10) mounted on the carriage, an inked ribbon (21) coiled within the ribbon cassette, a carriage drive motor (3) and drive belt (5) for reciprocating the carriage, and an inked ribbon take-up mechanism for taking up the inked ribbon in one direction by the reciprocative movement of the carriage, wherein the thermal print head is provided with a plurality of thermal element arrays (24, 25) having different pitches of thermal elements or different sizes of thermal elements.