Mill classifier fine-grinds and classifies materials such as grain, sugar, spices, glazes, protein, gelatin, cocoa and much more. The classifier mill utilizes a three to 200 hp motor and provides size reduction from 100 mesh down to low micron sizes. It combines classifying with grinding and its unique design normally provides a narrower spread of particle size than most other fine grinders. All material ground in the first stage enters a classifying chamber, next particles larger than specified are rejected by the classifier allowing only for properly sized product to exit the mill. All rejected material is directed to the third stage, which is a separate part of the grinding rotor, where it is processed until it is ground to an acceptable size. A secondary inlet provides additional air for the second stage internal air classifier. This additional air also adds an element of cooling to the material being processed. With its minimum temperature rise, it is especially effective on heat-sensitive materials such as sugar and cocoa. Grinding chamber and classifier access is through a common door that swings open for grinding element replacement and provides easy access to the complete product zone for cleaning.