PROBLEM TO BE SOLVED: To allow confirmation of whether a surface roughness measurement unit is operating for measurement or not without adding a signal line connecting the surface roughness measurement unit and a controller to each other.SOLUTION: Surface roughness measurement units 1 and 200 include: styluses 12, 233U, and 233D moving along a surface of a measurement object W; motors 28 and 240 which generate a driving force for moving the stylus 12 along the surface of the measurement object W or generate an urging force for bringing the styluses 233U and 233D into contact with the surface of the measurement object W; determination circuits 180 and 380 which determine whether the motors 28 and 240 are operating or not on the basis of motor application voltages applied to the motors 28 and 240; and display units 190 and 390 which display determination results of the determination circuits 180 and 380.
