Engineering structures such as plates, beams, and shells are subjected to different types of loads when used in applications such as bridges, buildings, and other structures. Due to the nature of loading cracks are produced in these elements over a period of time. These cracks will cause the failure of beams due to vibration. Vibration analysis is important to find the natural frequency of the structures. Modal analysis is performed to find the mode shapes and natural frequency of the cantilever beam. In the present investigation, a cantilever beam with crack is modeled and natural frequency for the first three modes is determined by using Ansys Workbench 19.2. The goal of the study is to change the length of the crack along the width of the beam and its effect on the natural frequency of the cantilever beam. During the study, the crack width is kept constant while the depth of crack is varied along with a change in the length of the crack. The crack with depth 45 mm and crack of length 50 mm gives a lower value of natural frequency.