Atomic force microscopy (AFM) enabled us to investigate the statistical properties of single polymer chains by a method called as “nanofishing”, which stretched a single polymer chain adsorbed on a substrate with its one end by picking it at another end. A force-extension curve obtained for a single polystyrene chain in a θ solvent (cyclohexane) showed a good agreement with a worm-like chain model, and thus gave microscopic information about entropic elasticity. Solvent effects on polymer chain conformations were also discussed. Nanofishing technique was extended for dynamic viscoelasitc measurement of single polymer chains. AFM cantilever was mechanically oscillated at its resonant frequency during stretching process. By this technique, we could quantitatively and simultaneously estimate elongation-dependent changes of stiffness and viscosity of a single chain itself with using a phenomenological model. The solvent effect on the viscosity in low extension regions was ensured that the viscosity under about 10kHz perturbation was attributed to monomer-solvent friction. These methods were proved to be powerful to give the experimental proofs against several basic questions in polymer physics and furthermore will unveil hidden properties of polymer chains or polymer solutions by any macroscopic measurements in the future.