The STM three dimensions surface shape appearance figure and scanning tunneling spectrum(STS) of nano-meter diamond are obtained by STM.IPC-205B developed by the authors.Insulator diamond films being transacted into nano-meter diamond particles,the STM three dimensions surface shape appearance figure of nano-meter diamond is gotten under a certain bias voltage.Then nano-meter diamond microstructure is observed.And the STS of nano-meter diamond is gained.Also it exhibits the energy gap breadth of nano-meter diamond.At the same time,the STS and conductive mechanism are analyzed.STM/STS studies can not only explain the spectrum study mechanism of conductive capability of nano-meter diamond and expand application field of STM,but also they may act as the important study means for nanometer crystal particles structure and energy spectrun character analyse after insulated material turns into nanometer crystal particles.