Abstract: Disclosed is a method for determining the degree to which parts, especially parts that are exposed to loads (11) which change over time, are damaged. According to the invention, the part (10) is actively excited (20). A sector of the surface of the excited part (10) is recorded by means of a thermographic apparatus (30) which records also small cracks, microcracks (15), and microplastic zones having a length or size of less than 2 mm on the surface of the part (10). The thermographic apparatus (30) feeds the recorded images with the small cracks, microcracks (15), and microplastic zones to an evaluation unit (40). The evaluation unit (40) systematically evaluates the represented distribution of the small cracks, microcracks (15), and microplastic zones according to a predefined process. The degree to which the part (10) has been damaged is determined from the evaluated data of the distribution of the small cracks, microcracks (15), and microplastic zones.