The invention provides a developing device which can determine and set the suitable amount of toner on a development roller, the suitable voltage to be applied to a compaction roller, and the number of rotations of the compaction roller according to the type of paper, thereby providing a high quality image. The developing device of the invention comprises a development roller to which a liquid toner containing toner particles dispersed in carrier liquid is applied by a toner supplying roller. A developed image is formed on a photoreceptor by the development roller. The device comprises a compaction roller for compacting the toner particles in the liquid toner on the development roller at a position before the development on the photoreceptor. The device comprises a means of controlling the number of rotations of the toner supplying roller according to the type of paper and a means of controlling the voltage to be applied to the compaction roller according to the type of paper. The device further comprises a means of controlling the number of rotations of the compaction roller according to the type of paper. Alternatively, the device comprises a means of controlling the voltage to be applied to the toner supplying roller relative to the voltage to be applied to the development roller according to the type of paper and a means of controlling the voltage to be applied to the compaction roller.