PROBLEM TO BE SOLVED: To provide a mammographic stereotactic device which selects a radiation dose detector placed in an optimal position.SOLUTION: A mammography apparatus 20 includes an imaging position information acquisition part 90 of a radiation source 30 and a breast 28 or an automatic exposure control (AEC) sensor 64 and a part 92 for acquiring position information of a radiation shielding member for acquiring radiation shielding position information on three-dimensional positions of a biopsy needle 52, a biopsy hand part, or a compression plate 38. A measurement position selecting part 80 includes a presumptive position excluding part 94 which determines whether a projection image generated on a detection surface of a solid-state detector 60 by a radiation shielding member constituting a part or all of the biopsy needle 52, the biopsy hand part, or the compression plate 38 overlaps a region corresponding to the position of the AEC sensor 64 on the detection surface or not based on the imaging position information and the radiation shielding member position information and excludes the position of the AEC sensor 64 determined to have the overlapped region out of the positions of a plurality of AEC sensors 64.COPYRIGHT: (C)2011,JPO&INPIT【課題】最適な位置に配設された放射線量検出器を選択することができる乳房撮影定位装置を提供する。【解決手段】マンモグラフィ装置20は、放射線源30、乳房28、又はAECセンサ64の撮影位置情報取得部90と、生検針52、バイオプシハンド部又は圧迫板38の三次元位置に関する放射線遮蔽位置情報を取得する放射線遮蔽部材位置情報取得部92と、を備え、測定位置選択部80は、前記撮影位置情報及び前記放射線遮蔽部材位置情報に基づいて、生検針52、バイオプシハンド部又は圧迫板38の一部若しくは全部を構成する放射線遮蔽部材によって固体検出器60の検出面上に生成される投影像と、AECセンサ64の位置に係る前記検出面上に対応する領域と、の重複が発生するか否かについて判定し、複数のAECセンサ64の位置のうち前記領域の重複が発生すると判定したAECセンサ64の位置を除外する推定的位置除外部94を備える。【選択図】図4