Provided is an inspection device such as a bone density measurement device, in which a mirror unit is disposed in order to observe the far side of a subject who is placed upon a loading surface. The mirror unit comprises a mirror member which moves rotationally. When an upper part comprising an x-ray detector rises upward, the force thereof is transmitted via a linking mechanism as a rotational movement of the mirror member. Thus, even is the viewpoint of an examiner is elevated, the mirror face is upturned, and it is possible to easily observe the far side of the subject, especially the lower part thereof. It would also be permissible to move the mirror member vertically in a sliding manner. It would also be permissible to dispose a light source in the mirror member. It would also be permissible to display a marker upon the mirror face.於骨密度測定裝置等之檢查裝置，為了觀察載置於載置面上的受測者內側，設置了鏡子單元。鏡子單元具備回轉作動的鏡子構件。將具備X射線檢測器的上部跳躍提升至上方時，其係藉由連動機構傳達鏡子構件之回轉作動。據此，即使檢查者的視點變高，由於鏡面變成朝上的緣故，可觀察受測者之內側，尤其可容易地觀察其下部。本發明亦可使鏡子構件向上下方向滑行作動。本發明亦可於鏡子構件設置光源。本發明亦可於鏡面上顯示位置標記。
