PURPOSE: To provide a radiation detector for the detection of a high energy particle beam such as an X-ray which is composed of an FT-CCD or an FFT- CCD which facilitates a high speed operation.

CONSTITUTION: The FT-CCD of the present invention is composed of a photoelectric conversion part 1, a storage part 2 and an output part 3. A vertical shift register (V) is composed of four electrodes which are arranged in parallel with each other for each unit picture element 11. The photoelectric conversion part 1 and the storage part 2 are composed of the vertical shift registers. A large number of the electrodes are provided in parallel with the longitudinal direction of the electrode and the longitudinal direction and the arrangement direction of the vertical shift registers are perpendicular to each other. Four-phase voltages (P1-P4) are applied to the respective electrodes to control the vertical shift registers. The output part 3 is composed of horizontal shift registers and an amplifier part 31. An electrode composed of a double-layer structure of polycrystalline silicon and metal silicide is provided on the surface of the photoelectric conversion part 1 and an X-ray transmitted through the electrode is detected by the photoelectric conversion part 1.