Adhesion, or the binding of different materials at an interface, is of general interest to many branches of technology, e.g., micro-electronics, tribology, manufacturing, construction, etc. In addition, varieties of plasma treatments for the adhesion control of polymers are still extensively studied by a lot of researchers. However, there is a lack of research that decreases the adhesion force by using plasma treatment devices. Thus, this paper study to decrease the adhesion force between a medical rubber, chloride-isobutene-isoprene rubber (CIIR), and stainless-steel SUS440C by using oxygen plasma treatment. The different adhesion forces were measure after plasma treatment with various methods. The elastic modulus was increased by oxygen plasma treated to the CIIR specimen. The results show that the elastic modulus was increased 15% to 28% as the plasma treated to the CIIR specimen. Experiment results showed that the adhesion force decreased by about 95-99.8% by using oxygen plasma treatments between CIIR and SUS440C. The different adhesion forces were explained based on the morphology and Attenuated Total Reflectance (ATR) FTIR.