This study is to compose the optimized membrane module process system to selectively separate and treat toxic gas emitted from the semiconductor process. To optimize the operation of membrane module process system to treat toxic gas, the inlet toxic gas toward the membrane module shall have equal flux and equal pressure. Therefore, if the inlet flux on the membrane may be equalized only with the adjustment of pipe diameter and arrangement without installation of devices such as flowmeter at the junction between distributing pipe and separation membrane, the pipe composition of membrane module process system may be optimized to reduce the cost as well. Here, the inlet gas pressure toward the membrane module shall be above 3 bar, and thus in this study, the system was established for gas to be compressed with the compressor to stably maintain the pressure at the inlet of membrane module. Accordingly, the flow and pressure of gas within the pipe from the compressor to the membrane module were evaluated through the numerical analysis to optimize the diameter and arrangement of pipe - eventually to be reflected on the on-site design. Based on the result of flow analysis, the 5,000 LPM fluoride gas separation system to be applied to the actual semiconductor process was established, and to confirm the separation and return efficiency of NF3, CF4, and SF6, in this study 1,000 ppm of highly concentrated NF3, CF4, and SF6 were injected into the system to check the rate of separation and return. The system was continuously operated for 300 hours, and in case of SF6 and CF4, on average of 93% or higher return rate and concentration ratio of 1 were maintained, while in case of NF3, on average of 90% or higher return rate and concentration ratio of 1 were maintained. Therefore, it was confirmed that the fluoride gas separation system may be applied as a low-energy consumption high-efficiency system for the electronic industry.