The invention relates to a thermal printer and a printing method thereby, using a step motor for feeding a sheet of paper, a scanning type thermal head and a control unit by which the paper feeding operation is temporarily stopped and the printing operation is restarted after the stopped period. This thermal printer further comprises a delay drive unit which drives the thermal head with delay of one or two clock periods, predetermined as a control parameter for this printing operation, by a phase switch timing point for the step motor, in response to the time-lag defined by the phase switch timing point to an actual paper feeding motion; and a pre-print unit which outputs a command signal to begin the printing operation of the thermal head for printing one or more times the print data which follows the final print data of when the paper feeding operation was stopped, prior to the above described regular drive operation of the thermal head at the restart of the printing operation. Whereby this thermal printer can provide a high quality print without any print gaps and unclear prints due to the interruption of the printing operation.