The aberration of electrostatic lens and deflection systems due to misalignment is analyzed for design of microfabrication systems. The potential for a lens and deflector having an electrode axis shift is approximated by introducing a shift function that expresses the electrode shift from the optical axis. On the basis of this approximation, mixed aberrations due to misalignment of lens and deflector electrodes can be analyzed, including the effect of a nonuniform electrode axis shift. Practical third order aberration coefficients are formulated in a compact form by eight integration functions, and are classified into 67 geometrical aberration coefficients and 4 chromatic aberration coefficients.