To provide a printer capable of controlling to eliminate a slack generated in an ink ribbon even if a previous preparative working such as setting an ink ribbon cassette after eliminating the slack of the ink ribbon is not performed.

Even if the ink ribbon is set in a printer in the state of the ribbon is slackened, a winding operation for eliminating the slack of the ribbon is being performed until the rotation of a ribbon feeding core part is detected with detecting the installation of the ribbon cassette. Accordingly, it becomes unnecessary to manually eliminate the slack of the ribbon before installing the ink ribbon cassette.