PURPOSE: To improve image quality, a developing speed, resolution, and background fogging by making the temperature of the surface of a recording material higher than peripheral temperature by ≤0.5°C while the surface of the ferroelectric recording material is in contact with voltage detecting toner particle dispersed liquid.

CONSTITUTION: A rotating toner applying roller 4 is arranged extremely closely to the surface of the ferroelectric recording material 2. A tank 5 housing the voltage detecting toner particle dispersed liquid 6 is arranged below the roller 4, so that the roller 4 is coated with the layer of the liquid 6 in the case the roller 4 rotates. The thickness of the layer 7 of the liquid 6 on the roller 4 is enough to be in contact with the material 2 at a toner applying interval 8. While the surface of the material 2 is brought into contact with the liquid 6, the surface temperature of the material 2 is higher than the peripheral temperature by at least 0.5°C. Thus, electric characteristic of the ferroelectric material is enhanced.