New poly(pyrrole-3,4-dicarboxylic acid) (PPyDCA) was synthesized by chemical and electrochemical polymerization methods. This new material was analyzed by vibrational and electronic spectroscopy methods. The IR spectra were obtained using different techniques: the KBr pellet method, attenuated total reflection (ATR), and specular reflectance techniques. The strongest IR bands are associated with dynamics of O-H center dot center dot center dot O complex. Detailed absorption spectra and optical conductivity spectra of PPyDCA are reported here that were carried out in polar solvent medium and in the solid phase. The theoretical analysis has also been performed for the PPyDCA species containing repeating units, up to fifteen. The geometric, electronic, and absorption properties of PPyDCA have been calculated using the time-dependent density functional theory and the density functional theory. The variation of electrical conductivity with temperature was observed. This phenomenon indicates the semi-conducing nature of pyrrole-3,4-dicarboxylic acid polymer with the activation energy of 0.71 eV within the temperature range between 120 and 380 K.