To provide an apparatus and method capable of measuring the strength of the film applied to the surface of a base material objectively, automatically and accurately.

The apparatus for measuring the strength of the film consists of a load tester 1 allowing load to act on a sample 6, an analogue/digital converter 8 inputting the load data outputted from the load tester 1, a CCD camera 9 for observing the entire surface of the film of the sample, an image processor 10 for analyzing the image signal of the CCD camera and a display monitor 11. In the method for measuring the strength of the film, the image signal of the CCD camera is inputted to the image processor to analyze the difference image with a reference image and the load data, at a point of time when the change quantity of the difference image exceeds a difinite value, is detected. Or, the edge extracted screen of a differential image is subjected to histogram processing and the load data, at a point of time when the variation exceeds a difinite value, is detected.