PURPOSE: To obtain an electrode in which influence of chlorine ions is remarkably small and response characteristic is enhanced by composing a sensitive film of sensitive substance for cadmium ions of specific derivative.

CONSTITUTION: When a sensitive film is formed of sensitive substance for cadmium of xylenebisthiocarbamate derivative represented by a formula I, acyclic ion compound containing sulfur as doner atom forms a stable complex with heavy metal ions and particularly Cd2+, a cadmium ion selective electrode in which influence of chlorine ions is eliminated and its response characteristic is enhanced is provided. In the formula, R is 1-9C alkyl group of normal or branched chain, and X is o- or p-xylene.