Shape measuring apparatus

A shape measuring apparatus comprising:

• a probe for scanning across a surface to be measured, while vibrating up and down;
• a minute-vibration generation section for vibrating the probe up and down;
• a vertical movement control section for moving the probe up and down to keep a constant contact force or a constant distance between the surface to be measured and the probe;
• a scanning section for scanning the surface to be measured with the probe;
• a displacement sensor for measuring vertical displacement of the probe and outputting a probe displacement signal;
• and
• a signal processing section for obtaining information about the contact force or distance between the surface to be measured and the probe from a high-frequency component, corresponding to the vibration of the probe, of the probe displacement signal output from the displacement sensor when the probe is brought closer to the surface to be measured while being vibrated, and for obtaining information about profile of the surface to be measured from a low-frequency component, corresponding to the profile of the surface to be measured, of the probe displacement signal output when the surface to be measured is scanned such that the distance or the contact force is kept constant.