A thermal printer includes a conveyance unit, a thermal head with heating elements arranged in a line crossing a conveyance direction of a thermal paper, and a controller that generates print dot data for dots to be printed by the thermal head and controls the conveyance unit and thermal head according to the print dot data. The controller determines whether the total number of dots to be printed in a predetermined number of consecutive lines of the print dot data is greater than a threshold number and, when the total number of dots is greater than the threshold number, control the conveyance unit to convey the thermal paper after the printing of the print dot data by a predetermined amount along the conveyance direction.