This report describes our recent development that mainly aims at the quantitative determination of hydrogen concentration in melt inclusions confined in minerals. The method is based on the proton-proton elastic scattering at 20 MeV. Since the stopping power of protons at 20 MeV is very small in materials as silicates, protons pass through a 200 μm thick sample without appreciable energy loss. It is feasible, therefore, to carry out non-destructive hydrogen analysis of melt inclusions with sizes in the range from a few tens to approximately 200 micrometers. Besides the depth profile of hydrogen, a map of the three-dimensional hydrogen concentration is observable using a scanning microbeam. An example is presented on a melt inclusion in quartz from pyroclastic rocks collected at Enda, Zaoh-machi, Miyagi Prefecture, Japan.