A contact heat fixing device which comprises a driving heated roller having a heating mechanism disposed in the interior thereof and a surface coated with an offset preventing material, a press roller which is rotated in intimate contact under pressure with said heat roller, a vessel for containing therein an offset preventing liquid and a feed mechanism for supplying the offset preventing liquid to the heated roller from the vessel, fixation of a toner image being accomplished by the passage of a support having the toner image thereon through the nip position of the heated roller and the press roller, wherein said feed mechanism includes an applicator for applying the offset preventing liquid to the surface of the heated roller and supply means for supplying the offset preventing liquid from the vessel to the applicator, said applicator being arranged so that it can shift between a position (PI) where it has a pressing contact with said supply means and a position (P2) where it has a pressing contact with said heated roller, in such a manner that the offset preventing liquid is supplied to said applicator when it is at said position (P1), the applicator is moved from said position (P1) to the position (P2) synchronously with feeding of said support to have temporary contact with the surface of the heated roller and apply thereto the offset preventing liquid, and the applicator is then returned to the position (P2).