Vibro-pneumatic separator has been applied widely in grain cleaning industries for separating light impurity, gravel and various types of contaminant from grain products. Pneumatic section is utilized as the suction part to separate the light impurity contaminant from the basic product based on the distinction of aerodynamic properties between basic product and impurities contaminants. A multilayer sieves equipped with vibration motor is utilized to separate the grain product from foreign materials other than grains such as sands and pieces of rocks based on the size. To improve the separation efficiency and productivity, several parameters need to be adjusted including the air velocity, vibration frequency and sieve angle. This study attempts to optimize the process parameter of a vibro-pneumatic separator based on the separation efficiency and productivity. An experimental design based on full factorial design was used to adequately adjust the process parameter of a vibro-pneumatic separator including air velocity, sieve angle and vibration frequency on cleaning paddy seeds from different types of contaminants. The effect of factors on each response are analyzed to study the effect of each factor on the desired responses. Multiobjective optimization using a response optimizer is functioned to obtain the optimal setup parameters of a vibro-pneumatic separator based on separation efficiency and productivity. The experiments revealed that vibration frequency was found to be significant for both separation efficiency and separation productivity, while air velocity and sieve angle factors were found to be insignificant for both separation efficiency and separation productivity. An increase in vibration frequency increased the separation efficiency and separation productivity. The statistical results confirmed that R2 of the regression models were 0.78 and 0.89 for the separation efficiency and separation productivity, respectively. According to the multiobjective response optimizer, the optimum setup was at 8 m/s of air velocity, 7 degree of sieve angle, and 20 m/s of vibration frequency. This appraoch enable us to determine the setup of separation machine based on more than one machining parameter using multiobjective approach.