The influence of substrate orientation on Be transport during GaAs molecular beam epitaxy is studied by secondary‐ion mass spectrometry. Substrates are misoriented from (100) toward (111)A, and the epitaxial growth is performed at 630 °C for Be doping at (5–7)×1019cm−3. Surface segregation and anomalous diffusion similarly depend on substrate orientation. With (311)Aorientation, the Be transport is dramatically reduced from its value with conventional (100) orientation. These results are qualitatively explained by considering the effect of atomic steps on the growing surface.