According to one embodiment, a wireless tag communication device detects a communication state between an antenna and a specific wireless tag to be searched, stores a transmission power value obtained if the communication state is better than a predetermined value, reduces transmission power to the wireless tag and, if the communication state is worse than the predetermined value, increases, on the basis of the stored transmission power value, the transmission power to be higher than the transmission power value and performs communication with the wireless tag, and performs resetting on the basis of the stored transmission power value if the communication state further worsens.