PROBLEM TO BE SOLVED: To provide an electronic cassette for radiography hardly transmitting heat to the interior of a housing from outside the housing via a transmission plate.SOLUTION: A transmission plate 27 of an electronic cassette has a three-layer structure from a first layer 81 to a third layer 83. The first layer 81, or the outermost layer, is constituted of a PITCH-based carbon sheet with a thermal conductivity of 150 W/mk or more. Since the carbon material with a relatively high thermal conductivity is used, heat dispersion is quick and the heat is hardly transmitted to the interior of the housing. The second layer 82 employs a PAN-based carbon sheet that has a relatively low thermal conductivity compared with the PITCH-based carbon sheet. The third layer 83 employs the same PITCH-based carbon sheet as the first layer 81 for preventing the warpage of the transmission plate 27.
