Abstract: A fixing device is provided for a wet type electrophotographic copying machine in which an electrostatic latent image formed on a photosensitive sheet at its face is developed by a liquid developer, and then the liquid developer attached to the photosensitive sheet is squeezed out by a squeezing device before the developed image is thermally fixed on the sheet. The fixing device includes a heater for heating the photosensitive sheet while the latter is being held at its back against the heater as the sheet moves thereon, the heater having a source of heat such as an infrared lamp or tungsten halogen lamp or nicrome wire rubber heater, and a roller made of air-permeable moisture-absorptive spongy material and located in confronting relation to the heater, the roller being pressable against the face of the photosensitive sheet. With such an arrangement, the developed image on the photosensitive sheet can be fixed reliably and thoroughly without fixing marks.