The identification of a particular illness is usually done by microscopic check-up from the phlegm, urine, blood, Rontgen, and CT-scan. This technique needs a long period, high cost, and complicated procedure. As a result, society feels reluctant to check up on their health. Thus, research of an instrument that can define and diagnose the illness easily, efficiently, and accurately is needed. This research developed a prototype of an electronic nose that consists of a gas sensor that can respond quickly the element of volatile organic through the breathing air. Principal component analysis (PCA) method is the most appropriate method to classify the type of illness visually. Therefore, this research is needed to be applied in medical instrumentation.