In accordance with one embodiment, a self-checkout apparatus comprises a reading module configured to read information of a wireless tag from a commodity attached with the wireless tag and housed in a storage room, and a data processing module configured to carry out sales registration and checkout processing of the commodity of which the wireless tag information is read by the reading module; wherein the reading module includes, inside the storage room, an antenna section for reading the information of the wireless tag from the commodity housed in the storage room, and a moving section for changing communication range of the antenna section with the wireless tag.