Different types of nano-cantilever specimens are fabricated from a macroscale multilayered thin film(silicon/copper/silicon nitride, Si/Cu/SiN) by using the Focused Ion Beam(FIB) based on the cantilever bending method in order to investigate the cracking behavior of nanoscale interfaces. For the single-mode interface cracking, a straight nano-cantilever specimen is fabricated. For the mixed-mode interface cracking, a double-nano-cantilever specimen is proposed to simultaneously apply bending and torque moments to the interface. All specimens are in situ loaded in the Transmission Electron Microscopy(TEM). In straight nano-cantilever specimens, the Cu/Si interface fractures due to a bending moment. In torsion nano-cantilever specimens, by changing the loading position, fracture experiments with different mode-mixities are successfully conducted. In addition, finite element analysis is employed to inquire the critical stress distribution on interface during the crack initiation, and stress concentration regions near the interface edge in all specimens are within the scale of 100 nm. In straight nano-cantilever specimens, the interfacial normal stress dominates the interface cracking, indicating a single-mode fracture. In torsion nano-cantilever specimens, the critical normal and shear stresses at crack initiation have a circular relation.