角分辨光电子能谱学 （Angle resolved photoemission spectroscopy，ARPES），是一种直接观测某固体里电子结构的方法，通常是利用极高的能量的光子，照射某固体，并且观察电子的散射，就可以知道某固体里的电子结构，这种技术对固态物理有很大的帮助。由于这种技术可以显示其准确度极高，曾今被喻为：一个可以看见电子结构的显微镜。(a microscope for where and how the electrons move)而到了今天，角分辨光电子能谱学仍是观察电子结构的最佳利器。

Angle-resolved photoemission spectroscopy (ARPES), is a direct experimental technique to observe the distribution of the electrons (more precisely, the density of single-particle electronic excitations) in the reciprocal space of solids. The technique is a refinement of ordinary photoemission spectroscopy, studying photoemission of electrons from a sample achieved usually by illumination with soft X-rays. ARPES is one of the most direct methods of studying the electronic structure of the surface of solids.