The laser-produced permanent electrical conductivity of the modifie poly(bis-alkylthio-acetylene), PATAC, lies between 10^-5 and 200 S/cm depending on the sample preparation and the laser irradiation conditions. The electrical conductivity of the modified PATAC is long-time stable without any special protection. The converted polymers are p-type semiconductors. The Hall mobility has been estimated between 0.01 to 8 cm²/Vs. The temperature coefficient of the resistance in the highly conducting state is low and lies between 10^-3 and 10^-4 K^-1. ESR at the 2-mm and 3-cm waveband was applied for the study of the spin dynamics, and the rates of the intrachain and interchain spin charge carriers were obtained. Depending on the conditions of the conversion and the applied temperature the polymer shows typical properties either of a semiconductor or of a metal