[en] When the electric field, F acts on a hydrogen atoms in Z-direction, the interaction energy between hydrogen atoms and the applied electric field may be represented by eFZ=eFrcos THETA =eF 3a₀/2 rho cos THETA. Suppose that hydrogen atoms are in the states of principle quantum 3. In the states, hydrogen atoms are degenerated, having nine wave functions of same energy. It was attempted to evaluate the first-order perturbation energies using degenerated perturbation theory, putting lambda H=eFZ. The calculated energies are as follows, W'=0, W'=+-95.26a₀eF, W'=+-13.59a₀eF. These values indicate that energy levels split into five. (author)