Photoelectron emission microscopy (PEEM) excited by hard X-ray photons has been extensively used in recent years by use of highly brilliant synchrotron radiation. In this article, we introduce principles, experimental setup, and some research topics of the hard X-ray PEEM. Especially, a visualization of buried interfacial nanostructures become possible in the use of hard X-ray PEEM, and the hard X-ray PEEM is thought to be a powerful tool for the investigation on surfaces and interfaces. We have also developed a nano-XAFS technique, that is, a microscopic XAFS measurement in 100 nm × 100 nm area using hard X-ray PEEM.
