Nano-sized materials such as nanobump, nanomesh, nanobelt were generated by thin film processing using interfering femtosecond laser beams. To split and interfere femtosecond laser, a demagnification system, with a cylindrical lens in some case, was used. With four interfering femtosecond laser beams, a nanobump array was generated from a gold thin film in a single shot. It became larger and a bead was formed at a top of a bump as the fs laser fluence increased. Moreover, with three or two interfering femtosecond laser beams, ellipsoidal or linear nanobump array was generated. As an application of nanobump array, field emission from a nanobump array was demonstrated for the first time. On the other hand, with higher fluence and four beams, nanohole array was generated, and nanomesh was also generated from nanohole array by scratching. Grating was also generated with two beams, and nanobelt was generated from grating by scratching. Bimetallic nanobelt was generated from multi-layered thin film.