A photo timer includes an X-ray dose detector for detecting the dose of X-rays irradiated from an X-ray irradiation apparatus, a stop-signal output means for outputting a stop signal to stop irradiation of the X-rays from the X-ray irradiation apparatus when the detected X-ray dose exceeds a predetermined value, and a communication means for sending the stop signal to the X-ray irradiation apparatus by wireless means. A radiographic apparatus includes the photo timer, a solid state detector for recording image information by irradiation of X-rays which carry the image information and outputting an image signal representing the image information, and a communication means for sending the image signal to a photography control means by wireless means. Further, cables are not required to connect the X-radiographic apparatus (photo timer) and the X-ray irradiation apparatus, or the X-radiographic apparatus and the photography control means.