For the vacuum interaction of a sphere in front of a plane, both obeying conductor boundary conditions, we consider the approximation of small separation. We derive the next-to-leading order of the asymptotic expansion in the separation-to-radius ratio ɛ. This correction is of order ɛ. In opposite to the scalar cases it contains also contributions proportional to logarithms in first and second order, ɛ In ɛ and ɛ(ln ɛ)². We compare this result with the available findings of numerical and experimental approaches.