A main unit, a lamp chamber, a graphite furnace analyzing section, a flame analyzing section, and a flame gas controller are sequentially placed from right to left. An autosampler is placed on the top of the lamp chamber. A housing section for a transformer and a power supply unit is provided behind the lamp chamber, the graphite furnace analyzing section, the flame analyzing section, and the flame gas controller. The housing section is used as a space for a power unit used for the whole atomic absorption spectrophotometer, as well as the graphite furnace analyzing section. The housing section is also used as space for a circuit board for controlling the whole atomic absorption photometer. The autosampler has a quadrangular sample tray. The autosampler drives an arm for holding an aspiration needle in the left and right directions and also in up and down directions.