PURPOSE: To enable to easily fit an ink ribbon without making operator's hands smeared, by a method wherein the tip side of ribbon guide arms can be rotated toward a leading-out part of an ink ribbon.

CONSTITUTION: A conventional ribbon cassette A' is used, and a cassette adaptor 10 is laied thereon to integrate both of the members to each other. By this, the leading-out part of the ink ribbon 2 exposed from the cassette 1 can be automatically stretched long in the exterior of the cassette 1 by using the ribbon guide arms 12, 12 when using. The thus stretched ink ribbon 2 can be easily fitted to ribbon guides 3, 3 in a click manner by holding the cassete 1 side. After thus fitting the ink ribbon 2, the cassette 1 is fitted to a predetermined position of a carriage C. After fitting the ribbon cassette A', the ribbon guide arms 12, 12 are folded to the inner side.