PURPOSE: To ensure that a printing ribbon can be fitted more easily than a spool-type one through a simple construction, by a method wherein an end part of a printing ribbon on the take-up side or the payout side is fitted to a reel contained in a cassette, which is placed in a printing head supporting device, and the cassette is moved together with the head.

CONSTITUTION: Where a reel 8 is a payout type reel, the operating condition of a reel shaft 9 is switched in accordance with the operation of the printer so that the reel 8 is rotated or stopped while, if required, setting the reel 8 in a predetermined rotation resistance condition. A reel 10 (take-up reel) is so driven that it is fixed to immobilize the printing ribbon 7 in a printing condition, and takes up the ribbon when the head-supporting device 4 is returned after completion of printing. Accordingly, since only one reel is provided in the cassette 6, the size of the cassette is small, and since the reel fitted to the machine frame is fixed during printing, the ribbon 7 can be securely held still during the printing, and the ribbon can be easily fitted thereon.