A contact cap is attached to a top cover of a camera of a dental tooth measuring apparatus, and when shooting, positioning of the tooth to be measured is performed with a bite section being slightly bitten by both of adjacent teeth sandwiching the tooth to be measured, and with keeping a state where the inside of the adjacent teeth is in contact with a camera side surface of a positioning convex section. Positioning of the tooth to be measured and the adjacent teeth with variation among individuals with respect to the camera can be performed more precisely.