It is well known that semiconductor devices are composed of a lot of surfaces and interfaces controlled at an atomic level. In a word, the semiconductor devices can't be made without the proof of the surface science. In this paper describes how the surface analysis was useful for the semiconductor industry. Especially, the outline is described about the result of evaluation for the dielectric thin film using XPS. It introduces the utility of Auger peak exited by Bremsstrahlung X-ray, the profile construction from angle-resolved measurements, the band alignments and the work function measurements as an evaluation example by XPS. It is thought that the finding clarified by the surface science becomes more important for the development of the semiconductor industry.