PURPOSE: To prevent the deterioration of an image quality due to the toner omission without damaging the image carrier by adequately selecting the condition of a separating pawl in a transfer paper separating device adopting the separating pawl consisting of resin for separating the transfer paper while coming into contact with the image carrier.

CONSTITUTION: The tip of the separating pawl 2 held in contact with the image carrier 1 is in a pyramidal shape, and when assuming the angle formed by the tangent of the image carrier 1 on the separating pawl contact point and the separating pawl contact face as α(°), the upper face projection pyramidal angle of the separating pawl 2 as θ2(°), the upper face projection tip radial of the separating pawl 2 as R(μm), the projection pyramidal angle of the separating pawl 2 in the rotary shaft direction of the image carrier l as θ1(°) and the projection tip radial of the separating pawl 2 in the rotary shaft direction as r(pm), the condition of the separating pawl 2 is set so that Bg, θ2, r, R, and αis severally provided with the respective value so as to satisfy the following numerical formula, 2tan(θ2/2)(R (1/sin(θ2/2)-1)+r(cos(θ1/2)/ tan-(α+(θ1/2)+1))<200.