Biscuits are products of confectionery technology process. They are made of a hard dough as the basic raw material contains flour, fat, sugar and other additives. Must be at least 6% of a fat based on the total weight of finished product with 5% water. For the purposes of Final thesis, a quality control of Koestlin Petit beurre biscuits and chemical analysis of their raw materials was conducted. In the process of experimental analysis, following methods were used: determination of water drying, determination inverta by Ofner, determine the percentage of free fatty acids, determination of iodine value by Hanus, determination of fat by Soxhlet, determine the quality of flavors, determination of sugars by the Luff - Shchoorlu, determine the pH of dough. The obtained samples of raw materials and finished products from production of biscuits, subjected to chemical analysis and rheological analysis of flour, meet the criteria of quality in accordance with current laws on food (NN 81/2013, NN 14/2014) with all the Regulations of the Croatian and EU directives. For each individual raw material, tests are conducted under the Plan of tests in order to be approved for further use in the production of Petit Beurre. The aim of Final thesis is to monitor the implementation process of Koestlin Petit beurre biscuit - analysis of raw materials and finished products, and based on the analysis define the sensory quality of finished product. Physico-chemical analysis of raw materials and finished products is carried out in the laboratory of company.