To efficiently perform a continuous information writing processing to a plurality of radio tag circuit elements with a minimum transmission output.

A radio tag information writing device includes: an antenna 14 for performing transmission/reception by radio communication between an IC circuit unit 151 storing prescribed information and the several radio tag circuit elements To having an antenna 152; the transmission part 32 of a high frequency circuit 21 for transmitting the position detecting signal of the radio tag circuit element To to the antenna 152; a receiving part 33 for receiving a return signal with the antenna 14, which is returned from the IC circuit unit 151 in response to the position detecting signal; and the transmitting part 32 for transmitting by non-contact via the antenna 14 radio tag information for performing writing in the IC circuit unit 151, based on the received return signal.