This manual explains the composition of Gas Chromatography (GC) and its characteristics by detector, using visual materials for better understanding. It is published to be used when using equipment by providing tips on equipment operation, precautions during operation, and its utilization. GC is a technique in which component separation occurs in a constant and consecutive manner between two non-mixing phases. It is developed for the purpose of dividing a compound into single components. Because a gas phase is used by vaporizing a sample at the inlet, good separation efficiency is observed. It features various advantages such as capillary column-based trace analysis, fast and accurate analysis of organic compounds, and easy control. This tool is used in analyzing volatile organic compounds in soil samples, drug components, additives in polymer (rubber, plastics, etc.) samples, and volatile organic compounds in water quality (drinking water and wastewater).