To always maintain a fixed distance between respective electrodes strictly in assembly of a cell or in an evaluation time by including an electrolyte in a liquid retaining material and arranging the respective electrodes pressedly via the liquid retaining material.

In a tripolar evaluation electrochemical cell, for example, liquid retaining materials such as glass wool including an electrolyte or solid electrolytes 4, 4 are arranged between a first electrode 1 and a third electrode 3 and between a second electrode 2 and the third electrode 3 respectively. The third electrode 3 is formed into a bored shape or the like desirably, so that it does not prevent the electrolyte from moving. The first and second electrodes 1, 2 are guided by means of a vertical electrode guide 7 so as to be pressed uniformly by means of plungers 6, 6 energized by springs 5, 5. In this structure, the respective electrodes 1-3 are accurately held opposedly to each other at fixed intervals. In a quadrupolar electrochemical cell, in which a fourth electrode is additionally arranged between a first electrode 1 and a second electrode 2, a similar structure can be accomplished.