A highly sensitive microscopic CCD detection system has been developed for the direct observation of local electron transfer reactions on an electrode surface. By monitoring the electrogenerated chemiluminescence (ECL) as a probe signal, two-dimensional mapping of the electrode surfaces could be performed with sub-micrometer resolution. This method was applied to the observation of the ECL reactions involving microcrystals of the oxidation product of perylene. By holding the applied potential on the electrode at 1.0 V, needle-like microcrystals of the perylene dimer cation radical salt were found to grow on the electrode surface. By applying sequential pulses of reduction and oxidation, intense ECL emission was observed on the microcrystals after the start of the pulse. With the time course of the redox pulse, reversed emission images were observed after 10-20 s, i.e. an intense ECL emission was observed on the backside of the microcrystals. These changes reflect the ECL reaction mechanisms involving the dissolution of microcrystals, whose dynamics were examined by observing the ECL images under various pulse sequences.