A commodity sales data processing apparatus determines, based on the imaged image of the commodity, whether or not the commodity is provided with an image display element for displaying a specific image representing that the commodity is a commodity adhered with a security tag, if it determines that the commodity is a commodity adhered with a security tag, the processing that the first resonant circuit become unusable for the security tag using the first communication device is carried out, in this state, if the first communication device carries out no communication and the second communication device carries out communication, carries out for shifting the processing of next commodity.