Suitability of potatoes for different processing directions is depended on their technological value and for direct consumption - on consumption quality. Irrespective of the utilization direction (consumption, food and industrial processing) the potatoes should satisfy the basic requirements, (i.e. appearance, mineral impurity content, tuber size, ect.) and be characterized by proper chemical composition including adequate contents of dry matter, starch, reducing and total sugars, vitamin C, total protein content and possibly the lowest contents of antinutritive substances. Chemical composition of the potatoes may be analysed by using traditional as well as modern methods (used in special laboratories). Often and often also the potato processing plants are fitted with the modern measuring equipment which enables the use of exact and fast methods, and provides precise determination of the quality of raw potatoes and their final products.