Abstract <p>Results are presented from studying the coercivity of three-layer magnetic films obtained via chemical deposition. Features of its changes from the thickness of the forming layers were determined. They are associated with the specificity of the magnetization reversal of the studied system, caused by a small difference between the values of the coercivity of the magnetic layers. The demagnetizing field energy is calculated and used to obtain an expression for the critical field of reversing the magnetization of the film. It describes the experimentally observed linear dependence of coercivity on the thickness of the magnetic layers.</p>