Scanning tunneling spectroscopy (STS) has been used to determine the band structure of polypyrrole. The polypyrrole films were electropolymerized onto a highly oriented pyrolytic graphite surface using a rotating disk electrode. Differential conductance spectra measurements allowed us to follow the evolution of the band gap as a function of doping level. Before and after the STS measurements, the film structure was imaged by scanning tunneling microscopy. The STS results agree with data obtained by inverse photoemission spectroscopy.