To obtain a thermal transfer recorder holding a variety of colors of ribbon cassette which can be replaced automatically.

A plurality of cassette holder plates 15 for holding ribbon cassettes 8 while stacking in a plurality of stages are arranged side by side on the plane facing a carriage of a holding cover 14 disposed oppositely to the carriage. The carriage is arranged with a carrier for replacing the ribbon cassette 8 by delivering the ribbon cassette 8 between each cassette holder plate 15 and the carriage. The ribbon cassettes 8 smaller at least one, in number, than the total number of ribbon cassettes 8 holdable on each cassette holder plate 15 are held on each cassette holder plate 15.