A large‐angle convergent‐beam electron diffraction (LACBED) pattern with fine diffraction lines from a cross‐sectional specimen of GexSi1−x/Si strained‐layer superlattices (SLS) can give much information on local strain and misfit stress relaxation. The shift of the diffraction lines in the GeSi layers from those in the Si layers can be used to determine the strain relaxation. A profile of the thin film relaxation versus the specimen thickness is presented. ©1995 American Institute of Physics.