A sheet conveying apparatus of an embodiment includes a conveyance path along which a sheet can be conveyed, and a plurality of conveyance rollers configured to move a sheet along the conveyance path. A wireless tag reader/writer is configured to read information from, and write information to, a wireless tag of a sheet on the conveyance path. A phase change detector is configured to detect a phase change in response waves received by the wireless tag reader/writer from a wireless tag. A tag specifying unit is configured to identify whether a wireless tag is moving along the conveyance path based on the detected phase change in response waves from the wireless tag. A controller controls the wireless tag reader/writer to write information to the wireless tag identified as moving along the conveyance path.