X-ray Photoelectron Spectroscopy (XPS) is a high-precision surface analysis instrument that measures the energy of photoelectrons emitted from sample surfaces under X-ray irradiation to quantitatively analyze surface chemical composition and chemical bonding states. It is used for thin film evaluation in semiconductor manufacturing, surface treatment analysis of metal processed products, bonding interface analysis of electronic components, and composition verification of coating films. The depth profiling function enables detailed analysis of ultra-thin layers from the surface to several nanometers, achieving quantitative evaluation of surface contamination and oxidation states in manufacturing process quality control, material development, and failure analysis. Also called ESCA (Electron Spectroscopy for Chemical Analysis), it performs comprehensive surface analysis in combination with AES (Auger Electron Spectroscopy) and SIMS (Secondary Ion Mass Spectrometry).