Printer

The disclosure discloses a printer includes a controller. The controller performs a first feed control process, a temperature-difference calculation process, and a first printing speed determination process. In the first feed control process, in a state where an energizing device does not perform energization to the heating element, the driving device is controlled to perform non-energization feeding while causing a thermal head to contact a print-receiving medium. In the temperature-difference calculation process, during execution of the non-energization feeding, a first deviation between two of the head temperatures which are respectively detected by the first temperature detecting device at different timings is calculated. In the first printing speed determination process, the printing speed is determined on the basis of the first deviation.