We have investigated the effects of electron beam (EB) irradiation on the optical and electrical properties of GaAs/AlGaAs heterostructures in the energy range between 5 and 25 keV. By using 10 keV-EB irradiation, the photoluminescence from quantum wells is shown to be degraded at doses higher than 1×1019 electrons/cm2, further, the two-dimensional-electron-gas mobility is degraded at doses more than 5xl020 electrons/cm2. EB irradiation of 5 and 25 keV, on the other hand, produces no degradation of both properties even at these dose levels. Such an energy dependence of EB-induced damage can be interpreted in terms of the EB energy dependence of the electron penetration and energy-loss-rate. Electrons with an incident energy of 5 keV do not penetrate sufficiently deep into the active region, and 25 keV electrons have an energy-loss-rate that is too low to cause damage.