PROBLEM TO BE SOLVED: To provide a radiation detecting device capable of both suppressing deformation of a support plate to which a radiation detecting panel is fixed and reducing weight. A radiation detection device (10) includes a radiation detection panel (40) for detecting radiation, a support plate (50) made of an MgLi alloy fixed in contact with the radiation detection panel (40), and a radiation detection panel (40) on the support plate (50). A plurality of tubular support columns 52 that are formed in contact with the opposite surface, a radiation detection panel 40, a support plate 50, and a support column 52 are housed, and a housing (rear member 30) arranged in contact with the support column 52 is disposed. ), And are provided. [Selection diagram] FIG.【課題】放射線検出パネルが固定される支持板の変形抑制と軽量化とを両立できる放射線検出装置を提供する。【解決手段】放射線検出装置１０は、放射線を検出する放射線検出パネル４０と、放射線検出パネル４０が接した状態で固定されるＭｇＬｉ合金製の支持板５０と、支持板５０における放射線検出パネル４０と反対側の面に接して複数形成された筒状の支持柱５２と、放射線検出パネル４０、支持板５０及び支持柱５２が収容され、支持柱５２と接して配置された筐体（背面部材３０）と、を備えている。【選択図】図２
