The growth process in the initial deposition stage of Ge films on an Si(001) surface where tellurium is adsorbed was investigated. The growth mode of these films was found to change to layered growth on a Te/Si(001) surface, i.e., Te atoms were observed on the surface of the Ge films as a result of successive site exchanges between the Te and Ge atoms. Thus, Te is believed to act as a surfactant to grow Ge in a layer‐by‐layer mode on a Si substrate. The growth process was observedin situby reflection high‐energy electron diffraction and low‐energy electron diffraction, with the microstructure of Ge films being examined in detail using a transmission electron microscope.