To provide a mill blank for dental CAD/CAM containing a ceramic material for preparing a dental restoration by being installed in a CAD/CAM device, wherein, the mill blank for dental CAD/CAM comprises a ceramic portion in which a dental restoration is cut out and a resin portion which joins with a CAD/CAM device, the mill blank for dental CAD/CAM has a columnar shape, the resin portion is provided at a side surface of the ceramic portion and has a cylindrical shape or a belt shape, a ceramic portion side of the resin portion contacts with the side surface of the ceramic portion, the ceramic portion has a columnar shape, the ceramic portion has a protrusion part, an upper surface and a bottom surface of the columnar shape of the ceramic portion are parallel to each other, the mill blank for dental CAD/CAM has at least two recesses which includes a first recess and a second recess in a circumference portion, the first recess and the second recess respectively include a first surface which is parallel to the upper surface and the bottom surface and a second surface which is a circumferential surface concentric with the circumferential surface of the mill blank for dental CAD/CAM and is vertical to the first surface, and the at least two recesses are formed within the resin portion.