The aim of this Master's Thesis is to describe an internal audit procedure in multinational company ČEZ, a. s., on the fictional sample of internal audit. The Master's Thesis is divided into theoretical and practical part. The theoretical part focuses on describing the basic concepts and processes of internal audit in general. The practical part deals with the internal audit process in a company which generate and sell electricity and heat. After studying company's documents related to internal audit was carried out fictitious internal audit. The main products of this audit are documents named Assignment of Audit and Final Report. Materials dealing with process of internal audit in this company are on high level and there wasn't any problem...