To improve the stability of running of an ink ribbon remarkably and thereby to enable maintenance of an excellent print quality for a long period.

In an ink ribbon cassette, an unwinding core 20 is provided and also a first friction means 14 which can come into contact with the lower lateral side of an ink ribbon 12 and a second friction means 18 which abuts on the inner peripheral side of the first friction means 14 and is made of a material having a smaller coefficient of friction than the first friction means 14 are provided inside the base of a cassette main body which is opposite to the lower lateral side of the ink ribbon wound on the unwinding core. At the time when the ink ribbon 12 is unwound from the unwinding core 20 in printing, it is unwound in contact with the first friction means 14 in the initial stage wherein it is unwound from a state of being wound fully on the unwinding core 20, and it is unwound in contact with the second friction means 18 after it comes out of the contact with the first friction means 14.