It is possible to discharge momentarily a gross electric current from an X-ray tube by use of the condenser type X-ray apparatus. This is true even if the source of electricity is weak in capacity or the output small. Preliminary studies of this apparatus have been made i foreign countries and then performed in our country. This apparatus was put to practical use by many investigators due to the quest for finding a suitable apparatus which could fill the need in our country where the electric service is not of the highest standard. The need also existed of finding an efficient apparatus for the diagnostic measurement against Tuberculosis. I have tried various control methods, and finally designed a method which reflecting upon the characteristic of reciprocity law failue of the roentgen film as follows : The X-ray is radiated to the object (patient) by use of the grid controlled X-ray tube, automatically controlled by the multiplier photo tube so as to produce an average brightness on the fluoroscopic screen which is illumined by the X-ray passed through the object. The X-ray film having an average blackness receive its image from the fluoroscopic screen by use of the photo timer. In this way, we were able to produce finer X-ray filme in the laboratory of our hospital. Modern control mothods in use up to this day were also discussed. Read at the sixteenth annual meeting of the Japanese Society of Rediological Technology. Sapporo, Hokkaido, Japan 2. July 1960.