A high-accuracy CNC surface roughness/form measuring instrument that allows simultaneous measurement of surface roughness and form/contour with one unit, and with only one detector. The X1- and Z1-axes feature a Laser Holoscale giving excellent narrow/wide range accuracy and resolution. An active control method is employed for the Z1-axis detector to implement a wide-range measurement capability wherein the variation in dynamic measuring force is restricted, and the detector also incorporates an anti-collision safety device to stop operation if a collision occurs with a workpiece or jig. A high maximum drive speed of 200 mm/s enables a potentially large increase in the throughput of multiple-profile/multiple-workpiece measurement tasks. The α axis enables continuous measurement over horizontal and inclined surfaces by power-tilting the X1 axis. Models with the Y-axis table allow expansion of the measuring range by repositioning in the Y-axis direction.