In sensor determination processing, each of a transmission-type optical sensor and a reflection-type optical sensor detects a label position, and first transport for transporting the printing medium is executed so that a first label position, which is detected by a first sensor succeeding in detecting the label position first, arrives at a printing position. When the first transport is terminated before a second sensor being another sensor succeeds in detecting a label position during the first transport, a first sensor is determined as a sensor to be used for detecting a label position. When the second sensor succeeds in detecting a label position during the first transport, a sensor succeeding in detecting the first label position or a second label position detected by the second sensor, which is closer to the printing position, is determined as the sensor to be used for detecting a label position.