A cleaning blade, for use in an image-forming apparatus, for removing toner which remains on a surface of a photoreceptor drum thereof, with the cleaning blade in contact with the photoreceptor drum. The cleaning blade is formed from a sheet composed of a thermosetting elastomer composition. The roughness degree of a ridgeline formed longitudinally on a cleaning blade edge which contacts the photoreceptor is set to not more than 10 .mu.m. The straightness degree of the ridgeline is set to not more than 100 .mu.m. In a test of supplying 150,000 sheets of paper conducted by mounting the cleaning blade on the image-forming apparatus, a change rate .DELTA.Re of an average roughness degree value Re of the ridgeline formed longitudinally on the edge is set to not more than +0.7, and a sectional length Ws45 of a wear surface of the edge, inclined at 45 degrees, which contacts the photoreceptor is set to not more than 50 .mu.m.