Exoelectron transmission through thin films is studied by evaporating non-exoelectron materials on exoelectron emission surfaces. The transmission curves through carbon and gold films are separated into two components, the thin film transmission part and the thicker film one. The decay rate in the later part shows almost the same tendency in various films and it is considered as a kind of diffusion process. This isan interesting result from the point of view of low energy electron transmission.