This manual explains the basic concept and operating principles of the AAS, using visual materials for a better understanding. It is published to be used when using equipment by providing tips regarding equipment operation, precautions during operation, and its utilization. This technique is faster, more accurate, and easier than other sample measuring methods with relatively little interference and good selectivity. Both high and low concentration can be analyzed. As equipment that protects the tester from the off-gassing that occurs during the use of the equipment, acid decomposition should be performed while using a gas mask. AAS is used in analyzing soil samples, drugs, polymers (ex: rubber, plastics, etc.), water quality, food (ex: agricultural products, fish, fruit, etc.), and wastes. It is also used in analyzing metal materials, ore components and semiconductor impurities.