  We discuss the energy of the excited 2$^+$ state in the unbound nucleus
$^{26}$O using the three-body model of $^{24}$O+$n$+$n$. This model fully takes
into account the continuum effects as well as the dineutron correlation of the
valence neutrons. The present calculation yields the energy of 1.354 MeV, which
is slightly smaller than the unperturbed energy, 1.54 MeV. The energy shifts
for the ground and the 2$^+$ states with respect to the unperturbed energy
suggest that 0$^+$ and the 2$^+$ states in $^{26}$O show a typical spectrum
well described by a short-range pairing interaction acting on two valence
nucleons in the same orbit.
