This chapter is devoted to introduce hydrogen (H) detection techniques for mappingMapping and depthProfiling profilingDepth profile together with their physical bases, which are the first step for the study of H kineticsKinetics in metals. Various techniques have been employed such as tritium luminographyTritium luminography, (autoradiography and imaging plate technique), H microprinting and Ag decoration, electrochemical microcellElectrochemical microcell or microcapillary cellMicrocapillary cell, surface potentialSurface potential measurement and Kelvin probe force microscopyKelvin probe force microscopy, atom prove tomography (APT), Secondary ion mass spectroscopy (SIMS), analyses using energetic particles and photons (ion beam analysisIon beam analysis, analyses using electrons and photons), electron microscopesElectron microscope, analysis using neutron, and some others. Because of its importance of quantitative determination of the amount of H dissolved and trapped in metalsThermal desorption, thermal desorptionDesorption spectroscopy (TDSThermal Desorption Spectroscopy (TDS)) is separately introduced. Finally, four important points are reminded for future work on HMapping mappingH mapping and depthProfiling profilingDepth profile; to observe (1) sequential changesSequential change of the H mappingMapping and (2) simultaneous H mappingsMapping of accumulated area and its surrounding area, (3) to determine the concentrationConcentration of H accumulated a local area or specified location, and (4) to know chemical formChemical form of the accumulated H.