The dark conductivity and photoconductivity of pristine poly(p‐phenylene sulfide) (PPS) were investigated under strictly controlled experimental conditions. Apparent dark conductivity of pristine PPS increased by more than a decade after the sample was irradiated with UV light. The appearance of apparent high conductivity was found to originate from thermally released electronic carriers which had been captured in deep trapping sites. Dark conductivity of PPS measured in air was about 4 decades higher than that measured under high vacuum. Oxygen absorbed in PPS samples was found to behave as weak electron acceptors and to assist the production of electronic carriers. Large photoconductivity under steady‐state photoirradiation was found.