  A new spin-ladder family material BiCu$_2$VO$_6$ is studied by means of the
magnetic susceptibility, heat capacity and neutron inelastic scattering
measurements on powder sample. Singlet ground state and a finite spin gap are
confirmed by thermal-activated type susceptibility and by distinct peak at 16
meV in spin excitation. Triple narrow band structure in spin excitation
spectrum, probably due to complex crystal structure, is observed and the
possibility of weakly-interacting spin-cluster system is discussed.
