The investigations of defects in thin layers are unfrugal. Most of the existing defect revealing methods are implemented only for thick layers or bulk material. The electrochemical, anodic etching technique can be a solution for defect exposure in thin SiGe layers. We present the investigations of samples, which consist of relaxed Si1-xGex layers (0 <= x <= 0.6) with different thicknesses (60-500 nm). The defect densities obtained by electrochemical, anodic etching agreed well with results acquired by traditional preferential etching with a modified Schimmel solution. Exact etch depth can be calculated from the etch current by Faraday's law. Additionally, electrochemical etching allows the investigation of defect densities in different depths by combining polishing and defect revealing etching conditions. (c) 2005 Elsevier B.V. All rights reserved.