Atomic absorption spectrophotometer comes with Deuterium lamp for background correction, RS232 interface, Multi-linear and nonlinear curve fitting. Its double beam system automatically compensates the light source drift and wavelength drift caused by the variation of temperature and electronic circuit drift so as to reach a good basic line stability. The specially designed fine light beam passes through the flame to ensure a high precision analytical test and low characteristic concentration in this atomic absorption spectrophotometer. It has multiple applications in research and development