The possibilities for the use of a scanning force microscope as a machining tool for the modification of gold surfaces were investigated. For this purpose, a scanning force microscope for the creation of structures with constant load and with a force modulation technique was constructed. With this instrument, we are able to create and characterize structures like lines and circles in thin gold films on mica. Especially the force modulation technique is suitable for producing structures with well defined geometry. Further investigations of the shape and the stability of the structures were made. ©1997 American Institute of Physics.