The photodisintegration of Be-9 in the energy region lower than E-gamma = 16 MeV is investigated by using the alpha + alpha + n three-body model and the complex scaling method. The cross section exhibits two aspects in two different energy regions. In the low-energy region up to E-gamma = 6 MeV, the cross section is explained by the transition strengths into the excited resonant states of Be-9, while the dipole transition into the nonresonant continuum states of Be-8(2(+)) + n dominates the cross section in the energy region of 6 <= E-gamma <= 16 MeV. Furthermore, it is shown that the dipole strength at E-gamma similar to 8 MeV is understood to be caused by the single-neutron excitation from the Be-8(2(+)) circle times nu p(3/2) configuration in the ground state.