NOVELTY - The method comprises assessing outer circumferential surfaces of a brick over the whole area with regard to characteristic parameters for the quality of silicon wafers, and separating the wafers to be processed from sections of the brick. The wafers fulfill predefined parameter values. The characteristic parameters comprises grain structure image, dislocation cluster proportion, and charge carrier lifetime. The grain structure images are taken from the outer circumferential surfaces of the bricks for determining area proportion of mono-crystalline regions.    USE - The method is useful for determining the quality of silicon wafers to be processed, which are sections of a brick separated from an ingot (claimed), where the silicon wafers are useful for producing semiconductor components such as a solar cell.    ADVANTAGE - The method is capable of determining the quality of silicon wafers in an easy and energy efficient manner.    DETAILED DESCRIPTION - The method comprises assessing outer circumferential surfaces of a brick over the whole area with regard to characteristic parameters for the quality of silicon wafers, and separating the wafers to be processed from sections of the brick. The wafers fulfill predefined parameter values. The characteristic parameters comprise a grain structure image, dislocation cluster proportion, and charge carrier lifetime. The grain structure images are taken from the outer circumferential surfaces of the bricks for determining area proportion of mono-crystalline regions, and are attached to a volume information. The charge carrier lifetime is determined by microwave detection or photoluminescence method, and is measured below a threshold value. The dislocation clusters are determined in each outer circumferential surface. The characteristic parameters are measured along a longitudinal axis of the brick at predetermined intervals, and the wafers are separated at a distance of the distance of 1D to 5D, where D is a thickness of the wafer.