PURPOSE: To provide a ribbon life detector capable of certainly detecting the life of an ink ribbon.

CONSTITUTION: When a printing signal is sent out of a printing control part, a detection circuit 6 detects the ink concn. of a cloth ink ribbon 2 at the position of an ink ribbon detection hole 5 and, when the ink density of the cloth ink ribbon 2 becomes a value incapable of obtaining desired printing quality, the output level of the detection circuit 6 becomes the predetermined level of a judging circuit 10 or more and, therefore, the judging circuit 10 outputs a life detection signal to a display part. A light emitting element driving circuit 11a is operated when the life detection signal is inputted and the light emitting element driving circuit 11a is operated and a warning light emitting element 11b lights to display the life of the ink ribbon on the display part.