To provide a method for analysis of low concentration hydrogen in solid samples correctly using a secondary ion mass spectrometry.

The hydrogen isotope of mass number 2, physical behavior of which resembles closely with that of hydrogen isotope of mass number 1, of very little abundance in the atmosphere as an elemental substances or a compound is introduced into a solid sample or an analytical object through ion injection. Then, the solid samples are heat-treated, resulted in reduction of concentration of hydrogen isotope of mass number 1 and mass number 2 contained in the solid samples, concentration of hydrogen isotope of mass number 2 is analyzed, based on a secondary ion mass spectrometry, and finally the number which remains in the solid samples is identified as a concentration of hydrogen isotope of mass number 1.