We have investigated the gettering efficiency at the interface of Si (110) and Si (100) directly bonded (DSB) substrates. DSB substrates were prepared by conventional bonding and grinding back methods. DSB substrates were intentionally contaminated with 3d transition metals (Fe, Ni, Cu) and then annealed at 1000 oC. The dependence of metal concentrations on the depth was evaluated by a secondary ionization mass spectrometer (SIMS). Furthermore, we observed the interface of DSB by transmission electron microscope (TEM), and characterized the form of the gettered metals.