PURPOSE: To provide a thermal printer which facilitates the cleaning of a thermal print head, by retaining the thermal print head at the print position or the separated position with a retaining lever charged by a spring.

CONSTITUTION: When printing, the outer end of the retaining lever 12 on a thermal print head 11 is engaged with a retaining hole 17 and a reaction to the contact force causes the thermal print head 11 to engage a platen. The thermal print head 11 is separated from the platen while turning the lever 12 to separate from the hole 17, and then the outer end 13 of the retaining lever 12 is brought into an elastic contact with the inner surface of a side plate 16. With contact friction, the thermal head 11 is rested at a desired position.