Industrial waste treatment becomes an environmental problem for the industry. Oil water separator is one solution to solve environmental problems in industry. Oil water separator is used as an industrial waste processor to obtain safe waste for the environment with the level of acidity or pH reaches the number 7 which means the waste is neutral in accordance with the standard water standards. The use of CPI (corrogurated plate interceptor) as a waste processor is only able to separate the size of droplets with the smallest size of 50 microns but has a faster process than EC (electro coagulant). The use of EC as a waste treatment can separate droplets below 50 microns. Oil water separator is generally separated between the CPI and the EC so that in the design of this tool developed oil water separator with the incorporation of CPI and EC. The purpose of this design is to get a faster processing time of waste and pH value reached number 7. Waste processing begins with CPI process and then proceed with EC process. The construction consists of a box tank containing CPI and EC components with an overall dimension of 2000 mm x 1000 mm x 1000 mm. CPI has dimensions of 850 mm x 260 mm x 310 mm. EC plates have dimensions of 600 mm x 650 mm x 3 mm with the number of plates of 10 pieces, 5 plates as a positive pole and 5 negative pole plate. The capacity of waste processing process is designed to separate water with oil as much as 1 m3 / hour.