The growth of high‐purity GaAs by chemical beam epitaxy using triethylgallium and arsine is reported. Purity of the epilayer is affected by the cracking efficiency of arsine, V/III ratio, and the substrate temperature. Samples generally showp‐type conductivity with carbon as the residual impurity. The growth conditions to achieve net carrier concentration below 1014cm−3are identified. The low‐temperature photoluminescence spectrum shows well‐resolved excitonic structures, an indication of excellent optical quality.