A handheld X ray device comprises a camera-like X ray generator body having a zoom ring-like object at a front side of the X ray generator body as an exit of X rays and has a collimator section atop a surface of the zoom ring-like object. The camera-like X ray generator body inside has a voltage boosting circuit, an oscillator circuit, a battery, and a control circuit, and a user interface at a real panel of the camera-like X ray generator body. The glass ball-tube is a cold cathode type X-ray generator with a tungsten filament at a periphery of a cold cathode. The voltage boosting circuit, the oscillator circuit, boosting the voltage of the battery up to a predetermined high voltage under controlled of the control circuit assisting by the user interface.