Recently, global scientists have drawn attentions of study of graphene. Graphene has a lot of potential applications in nanoelectronics and nanophotonics. We have demonstrated to use an electric-field-assisted method to manipulate graphene flakes between metal micro electrodes successfully. The size of the graphene flake can be as large as 15 μm x 15 μm. I-V characteristics of the graphene flakes were obtained and the results indicate that the graphene is a zero band gap material which is consistent with many other studies. Different thicknesses of graphene flakes were measured by using an Atomic Force Microscope (AFM). The measurements also confirmed with Raman spectra and showed that the graphene flakes were few-layer-graphene (FLG) and multi-layer-graphene (MLG). The results demonstrate high potential applications of the electric-field-assisted technique and AFM for the investigation and nanomanipulation of graphene at the nanoscale.