A switch in carrier transport from X–X to Γ–X–Γ is found in a GaAs/AlAs type-II superlattice under an electric field. This phenomenon is caused by an X–Γ transfer, as demonstrated by the photoluminescence, photocurrent response, and current–voltage characteristics. Under a high electric field, most of the electrons flow through the Γ path even in type-II superlattices.