PURPOSE: To measure the area of a surface automatically and to measure hardness automatically based on the (measured value) a Vickers hardness tester.

CONSTITUTION: A tester 1 pushes an intender into the surface of a test piece with a specified load. A TV camera 13 is attached to the eyepiece part of the tester 1. A digital image recording part 20 records the image of a recess from the TV camera as the variable density image. A noise processing part 21 performs the two-dimensional smoothing of the recess image recorded in the image recording part and selectively removes a flaw. A recess-boundary detecting part 22 extracts the boundary point of the recess out of the points, where the changing rates of the luminances become the maximum values for the image signals processed with the noise processing part. A recess-apex detecting part 23 obtains the positions of four apexes of the recess based on the boundary of the recess obtained with the recess-boundary detecting part. These parts are provided. The length of the diagonal line is measured based on the positions of the apexes obtained with the recess-apex detecting part 23. The hardness is operated with a hardness computing part 24 based on the measured value and the pushing load of intender. The result is printed with a printer 25.