A nuclear medicine diagnostic apparatus includes a support unit for supporting an inspection object from front, an opening for receiving a breast of the inspection object supported by the support unit, a detector ring opposed to the inspection object across a supporting surface of the support unit for detecting radiation generated from the breast, a chest mat provided around the opening formed in the support unit for supporting the chest of the inspection object, and an outer mat provided outward of the chest mat for supporting the inspection object. The chest mat is formed of a material having a greater sagging rate than the outer mat.
