Thermoelectric SiGe film and catalyst Pt film with a suitable area ratio were prepared in sequence on a thermally oxidized silicon substrate by RF-sputtering method. Their crystalline phase and microstructure were characterized by the methods of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Hydrogen-sensing properties of the multi-layer device Pt/SiGe were investigated in turn at modest operating temperatures ranging from 60 to 120degreesC. The influence on the sensing characteristics from the preparing condition of SiGe film and Pt film was discussed in detail. Besides, the detectable range of hydrogen concentration, the response and recovery time for the present device structure were also presented. (C) 2003 Elsevier B.V. All rights reserved.