The algorithm of the electromagnetic environment estimation inside a cinema and concert hall control room, equipped by diverse (on power, sensitivity, frequency range and so forth) hardware, is proposed. The modeling program has been developed to simulate the indoor electromagnetic environment. The area of hardware control room is conventionally represented by two dimensional grids of cells for modeling the electromagnetic environment. The electromagnetic power is calculated as a solution of the system of equations for each cell. The suggested program also provides information about the impact of each single equipment unit on the electromagnetic environment within investigated area. The obtained data make it possible to make decisions on the use additional means to ensure the electromagnetic compatibility, such as: rational location equipment, application of screens, radio frequency interference filters, etc.