The main part of the master thesis is related to an evaluation of a crack depth in concrete by using a non-destructive method called Impact Echo. The theoretical background of the wave propagation in elastic solids and the related finite element method are presented. In the experimental work we performed measurements on two sets of cracks. The first set consisted of four vertical cracks of different depths: 149 mm, 119 mm, 88 mm and 58 mm. The second set consisted of cracks of specific configurations. We used the experimental procedures described in the book . For a crack depth of 149 mm a numerical simulation was done by using the finite element method and Abaqus computer code. Comparison of the experimental and numerical results is presented in the tables and graphs. The numerical simulation accurately predicts the results.