Abstract
Direct current (dc) electrochemiluminescence (ECL) of tris(2,2'‐bipyridine)ruthenium(II) 
was observed in acetonitrile solution by using an Al‐sheet working electrode at negative potential. The dc ECL was originated from the excited state of 
. Characteristics of the luminescence were as follows; (i) the luminescence was continued for several hours, (ii) response time of the luminescence was faster than that of alternating current ECL, and (iii) the luminescence was observed all over the sheet electrode.