An image forming device capable of reducing resources related to destruction of a wireless tag is provided. The image forming device according to the present embodiment includes a reader and writer, a fixing unit, a determination unit, and a control unit. The reader and writer reads information from the wireless tag. The fixing unit heats and conveys a sheet having the wireless tag. The determination unit determines a defect of the wireless tag based on a reading result of the reader and writer. If the determination unit determines that the wireless tag is defective, the control unit controls the fixing unit to increase an amount of heat applied to the wireless tag such that information cannot be read from the wireless tag.