The present invention provides a rapid coulometric analysis for the quantitative determination of a sample substance with high reproducibility without any application of voltage etc. from the outside, as well as a galvanic cell and a device for use in said coulometric analysis. According to the present invention, a wide variety of components can be analyzed by selection of electroactive substance introduced into the galvanic cell. The present invention enables a simple and easy analysis for food components such as glutamic acid, ascorbic acid, etc., water quality such as COD, etc.