PURPOSE: To measure the hardnesses of a surface layer and a thin film by providing a scanning mechanism wherein an indenter which is supported with a plate spring is brought into contact with a light load and scanning is performed through a laminated piezoelectric element to which the plate spring is fixed, and detecting the displacement of the indenter with a displacement sensor.

CONSTITUTION: An indenter 1 which is supported with a plate spring 2 is pushed to a surface to be measured 3A with a laminated piezoelectric element 4. In this step wherein the indenter 1 is pushed and separated, the deflecting amount of the spring 2 is measured based on the amount of the displacement of the element 4 with a displacement sensor 5 and the indenter 1. Thus a load-displacement curve is obtained, and the amount of elastic deformation and the amount of plastic deformation are found. Since a load and the rigidity of the spring are known, the deflecting amount of the spring 2 is measured after the contact of the indenter 1. Thus the amount of application is found. Then the load of the indenter 1 is decreased to a very small value to the degree where the surface is slightly deformed elastically. When a member to be measured 3 is moved, the spring 2 is displaced in response to the shape of the surface to be measured 3A. The displacement is detected with the sensor 5. The shape of the indentation is found based on the moved amount of the surface to be measured 3A and the displacement of the spring 2. Therefore, details such as the depth distribution of the indentation and the rising-up state of the surrounding part can be displayed.