Electrical properties of LaB6/GaAs(001) Schottky diodes have been studied by current‐voltage measurements. The diodes were made by depositing LaB6on chemically etched GaAs and molecular beam epitaxy prepared GaAs‐c(4×4) surfaces by electron beam evaporation. The barrier height and ideality factor show appropriate values for metal‐semiconductor field‐effect‐semiconductor application and do not change much by high‐temperature annealing. These results provide firm evidence that LaB6is a very promising candidate for self‐aligned gate material of GaAs integrated circuits.