Electron focusing effect is observed in a two‐dimensional electron gas using samples with simple multiparallel one‐dimensional channels made by a Be focused ion beam (FIB). Subharmonics and harmonics are resolved; their strengths allow a direct determination of the elastic scattering lengthle=1.8 &mgr;m and the specularity coefficientp=0.35 for electron reflection at the boundary defined by the FIB. The temperature dependence of the focusing effect is much weaker than the Shubnikov–de Haas effect.