To provide a control method for an IC reader-writer suppressing electric power consumption of a transmission part while carrying out radiation limit of a sideband and suppression of spurious emission.

The control method for the IC reader-writer is provided with a transmission power supply turning on step of turning on a power supply of the transmission part 22 before sending a polling for detecting an IC card 80, a transmission output turning on step of turning on an output of the transmission part 22 while suppressing a radio wave other than a conveyance frequency after passage of a predetermined time from turning on the power supply of the transmission part 22, a polling sending step of sending the polling, a transmission output turning off step of turning off the output of the transmission part while suppressing the radio wave other than the conveyance frequency when a negative acknowledge to the polling sent in the polling sending step is received or when a response time to the polling has passed, and a transmission power supply turning off step of turning off the power supply of the transmission part 22 after the output of the transmission part 22 is turned off in the transmission output turning off step.