PURPOSE: To prevent a toner from moistening the reverse surface of recording paper by providing at least two drive sources for applying a carrying means with different- speed carriage force and by changing carrying speeds at the timing when the leading and tailing edges of the recording paper meet the toner.

CONSTITUTION: Recording paper 2 cut to an adequate length is carried to developing device 12 by capstan 11 and pinch roller 10 and at this time, adsorption conveyor 20 is driven by motor 4 at a low speed. Then, recording paper 2 is carried at a speed lower than the peripheral speed of rotary drum 14 and, when the leading edge of recording paper 2 meets toner 13, never picks up toner 13. As the leading edge of recording paper 2 is detected by sensor 32, adsorption conveyor 20 is driven by motor 30 at a high speed and recording paper 2 is therefore carried at the high speed, so that when the tailing edge of recording paper 2 meets toner 13, toner 13 does not cover it.