Trapping of low energy deuterium ions is investigated at inclined ArD + bombardment of Nb target. The trapping coefficient η, which is found from the thermal desorption spectra after implantation, is measured for the energy range of 5–120 eV per deuteron at 60°angle of incidence. The value of η measured for target cleaned with Ar bombardment and temperature treatment decreases with energy from η∼0.3 at the primary energy E 0=120 eV to η∼0.15 at about E 0=5 eV. Computer simulations based on the binary collision approximation and performed with taking into account the real target micro relief measured with STM agree with the experimental data rather well.