PURPOSE: To easily measure the salt content of cured org. and inorg. matter by partly sampling the cured org. and inorg. matter, forming the same into powder, adding an acid to the powder to generate gaseous hydrogen chloride and visually observing the amt. of the generated gas from the discoloration of an indicator.

CONSTITUTION: A small hole is bored to the cured inorg. matter, for example, concrete and a part of said matter is sampled to obtain concrete powder 12 which is then put into a measuring instrument 15. Potassium dichromate is put as a catalyst into the instrument 15 and is mixed with the concrete powder 12. Concd. sufluric acid is added from a sprayer 18 through an injection pipe 19 to the mixture of the concrete powder 12. The salt contained in the concrete powder 12 is decomposed by the concd. sulfuric acid to generate the gaseous hydrogen chloride. Indicator-impregnated filter paper 16b covering an aperture 16 discolors according to the degree of the generation of the gaseous hydrogen chloride. The cured org. and inorg. matter is sampled and the gaseous hydrogen chloride is generated by the acid, then the discoloration of the indicator is visually observed in the above-mentioned manner; therefore, the salt in the cured matter is easily measurable.