A tungsten tip and an iron-coated tungsten tip were used to investigate cobalt phthalocyanine molecules absorbed on a Au(111) surface. Similar STM images but different STS curves were obtained above the central part of the molecules. Theoretical analysis points out that the delocalized orbital of ligands hybridized with the Au surface at 0.4 eV below Fermi level can be detected and enhanced with an iron-coated tungsten tip due to the extended spatial distribution of the frontier orbital in the tip. As the spatial distribution of the frontier orbital in the tungsten tip is localized, the hybrid state cannot be detected above the central part of the molecule. These results indicate that the appropriateness of selection and preparation of the STM tip can probe richer chemistry and physics on surfaces.