The cleaning of the GaAs (111)B surface with a hydrogen electron cyclotron resonance discharge plasma is investigated at temperatures between 200 and 500 °C and compared with the GaAs (100) surface. It is found that during the exposure the GaAs (111)B is etched in a non‐Arrhenius way with a higher etch rate at low temperatures. For temperatures 300–500 °C, the surface is severely roughened after exposure, while the (100) surface remains smooth in all cases. The near‐surface crystalline quality of GaAs (111)B remains higher than that of (100).