A response surface methodology (RSM) has been utilized for investigating the effects of the speed of shelling, melon seed moisture content and the number of beaters of a developed mechanized centrifugal melon shelling and cleaning machine. The machine shells the melon and then cleans the shelled seed from the shells and other impurities. The experiment was based on a central composite rotatable design (CCRD). The results of the experiments revealed that the highest shelling efficiency of 88.5% was obtained from a combination of a speed of 2300 rpm, moisture content of 15% (w.b) and 20 beaters, while the least efficiency of 25.11% was obtained from an interaction between a speed of 959 rpm, moisture content of 20% (w.b) and 18 beaters. Numerical optimization carried out with the goal of maximizing the shelling efficiency revealed optimum values of speed of 2200 rpm, moisture content of 12% (w.b) and 19 beaters for shelling efficiency of 88.80%. The result of this study provided standard input parameters capable of yielding high cleaning and recovery efficiency.