In one embodiment, a commodity sales data processing apparatus has a data processing terminal and a docking station. Further, the commodity sales data processing apparatus has a connection mechanism and a lock mechanism. The connection mechanism connects the data processing terminal and the docking station in a separable state. The lock mechanism locks connection by the connection mechanism, so as to make the connection by the connection mechanism from in the separable state to in an inseparable state. Further, the lock mechanism releases locking of the connection by the connection mechanism when a specific key operation is performed.