In order to develop a technique for TEM examinations of wire-bonded interfaces, which is important to solve problems in the IC industry, thin films with intermetallic interfaces were prepared by an ultramicrotome technique. There is no amorphous phase in these films, whereas in the films prepared by ion milling, the interfaces has become amorphous. From this result, a suitable technique to prepare films of wire-bonded interface is discussed, for TEM microscopy.