[Problem] To provide a surface roughness inspection system enabling suitable inspection even when the surface of the object being inspected is curved.[Means for Solution] A system having an imaging unit 20 having a line sensor 22 and scanning the surface of an object being inspected 101 in a direction perpendicular to the direction of extension of the line sensor 22 and outputting a density signal for each pixel from the line sensor 22 and a processing unit 50 processing the density signal from the line sensor 22 of the imaging unit 20, the processing unit 50 having a means for acquiring a pixel density value based on a density signal from the line sensor 22 (S2) and a density state generating means for generating a density state information Pf showing the density state in the scan direction of the object surface based on all of the pixel density values acquired for the object surface 101 being inspected (S7).