An electrochemical measurement apparatus includes: a tank containing electrolytic solution and a sample that generates or consumes measurement target substances in the electrolytic solution; a plurality of uniformly mixed working electrodes; and a counter electrode; the apparatus adapted to simultaneously apply a voltage between each of the working electrodes and the counter electrode; and the apparatus configured to measure a current that flows between each of the working electrodes and the counter electrode; wherein any two working electrode groups are mutually different in at least any of the determined voltage, presence/absence of a molecular modification of an electrode surface, and a species of the molecular modification; and whereby a distribution in measurement area of the currents that flow through the working electrodes is acquired.