A head drive device includes a thermal head, a capacitor, a control circuit and a drive circuit. The thermal head has a first group of heat generators and a second group of heat generators having a smaller number of heat generators than the first group. The control circuit selects, based on printing data, whether to perform printing with use of the first group or to perform printing with use of the second group. The drive circuit supplies power of a power source and the power stored in the capacitor to the thermal head when the first group is used, and supplies the power of the power source to the thermal head when the second group is used. The control circuit performs printing with use the first or second group based on the storage state of the capacitor.