A device for fixing a toner image on an image supporting member includes a first and a second roller for conveying the image supporting member while holding it therebetween and fixing the toner image on the image supporting member, and an applicator being in contact with the first roller and applying offset preventing liquid to the first roller. The portion of contact of the applicator with the first roller is provided with a first portion contacting the fixing action area of the first roller and a second portion including the end areas of the portion of contact with respect to the lengthwise direction of the first roller. The applicator has, in at least the portion of contact, a liquid amount control member formed of synthetic resin having fine continuous pores. The offset preventing liquid oozes out to the surface of the synthetic resin through the fine continuous pores and is applied to the first roller. The applicator further has an obstructing member for obstructing the ooozing of the offset preventing liquid from the second portion of portion of contact.