The radiation image detecting apparatus

PROBLEM TO BE SOLVED: To improve the SN ratio.SOLUTION: A scintillator 20 has a plurality of columnar crystals 31 formed of CsI:Tl, converts X-rays into visible light, and emits the visible light from tips 31a of the columnar crystals 31. A surface protective film 23 is formed of poly-para-xylene, and covers the surface of the scintillator 20. The tips 31a of the columnar crystals 31 penetrate into the surface protective film 23. A photoelectric conversion panel 21 is composed of a glass substrate 21a and an element part 21b formed on the glass substrate 21a. The element part 21b has a plurality of pixels, is placed oppositely to the tips 31a of the columnar crystals 31, and detects the visible light, which is emitted from the tips 31a and passes through the surface protective film 23, on light-receiving regions of the respective pixels to convert the visible light into charges. A penetration amount P of the tips 31a into the surface protective film 23, and a light-receiving region area A of each of the pixels are set so as to satisfy the relation 0