Patent ID: 7100429

Claim:
A surface profile measuring instrument for measuring a surface profile of a workpiece, comprising: a probe having a stylus provided with a measuring portion for measuring a surface of a workpiece at a tip end thereof and a detector for outputting a detection signal which varies depending on a measurement condition between the surface of the workpiece and the measuring portion; a scanning mechanism for relatively moving the measuring portion along the surface of the workpiece; a sampling unit that samples linear position information of the measuring portion when the detection signal reaches a predetermined reference signal value; a response variation factor calculator for calculating a response variation factor based on the linear position information of the measuring portion when the detection signal reaches the reference signal value, the response variation factor applying variation to a response of the detection signal from the surface of the workpiece; and a profile processor that corrects the linear position information to obtain an actual profile of the surface of the workpiece using the response variation factor.