This chapter shows how analytical and spectroscopic techniques can be used to: (i) understand the mechanisms of adsorption in MOFs, (ii) highlight any effects of adsorption on the framework structure, chemistry, and overall stability, and (iii) quantify adsorption equilibrium and kinetics. The chapter provides the reader with the basic knowledge and skills to understand the current literature in terms of the tools typically employed to characterize adsorption in MOFs. Through examples from the published studies, it also shows the readers how to plan their own experiments based on the information sought. Each chapter subsection relates to a different class of characterization techniques: spectroscopy (X-ray diffraction, neutron diffraction, X-ray photoelectron, X-ray absorption, UV–Vis, infrared, Raman, nuclear magnetic resonance, electron paramagnetic resonance, inductively coupled plasma), gas sorption, thermogravimetric analysis, and magnetic susceptibility.