Decay properties of an isotope 266Bh and its daughter nucleus 262Db produced by the 248Cm(23Na,5n) reaction were studied by using a gas-filled recoil separator coupled with a position-sensitive semiconductor detector. 266Bh was clearly identified from the correlation of the known nuclide, 262Db. The obtained decay properties of 266Bh and 262Db are consistent with those observed in the 278113 chain, which provided further confirmation of the discovery of 278113.