PURPOSE: To surely separate a recording sheet by specifying the radius of curvature and a winding angle at a position where the recording sheet is separated from a conveying belt.

CONSTITUTION: Out of pulleys to which the conveying belt 18 is wound, a pulley 18A on a side where the recording sheet is fed to a fixing device 19 is grounded, and electrostatic charging quantity is gradually softened from the conveying belt 18 which approaches the pulley 18A so as to weaken electrostatic attractive force to the recording sheet. Meanwhile, a position where the belt 128 comes to the pulley 18A on the grounded side is set as the separating position of the recording sheet, and the radius of curvature (r) at the separating position is set at ≤7.5mm and the winding angle θ to the pulley 18A there is set at ≥60°. Thus, the recording sheet causes a state where force that it is restored to a plane state by the elastic repulsive force of its own excels and it is restored from a wound state to the condition at the time when it is fed. Then, it is peeled off from the pulley 18A and the recording sheet is surely separated.