On a new double-product centrifugal classifier, we simulated numerically and performed classification experiments. Consequently, we reached the following conclusions. (1) We get the scaling law of the cut size by the numerical simulations. (2) Flow-visualized structure of a steady almost rigidly rotating flow agrees with numerically simulated one. (3) We obtained the experimental performance that agrees qualitatively with the simulated one under the condition of increasing water-supply.