Provided are an X ray image photographing apparatus and a method thereof. The X ray image photographing apparatus and the method thereof according to the present invention verify the effectiveness of an automatic exposure request signal in detecting the X rays radiated from an X ray generator and photographing an X ray image using the self generated automatic exposure request signal thus preventing an undesired automatic exposure request signal from being generated by vibration temperature change noise or the like and thus improving the reliability of an X ray photographing operation and an photographed X ray image.
