Abstract: In this work, expressions for the steady state voltammetric curve of a microdisk electrode are derived by using "uniform concentration" approach. For reversible electrode reactions, the derived expression is exact, while for irreversible and quasireversible reactions, the expressions are approximate.In the case of irreversible reaction, the maximum relative error of the current calculated from the given expression is about 4%. The approximate expression has the form similar to those for conventional planar electrodes. The relation between the upper limit of measurable rate constant and the radius of microdisk electrode is also discussed.

Key words: Microdisk electrode, "Uniform concentration" approach, Stead State electrochemical behavior