One of the approaches to the description of complex dynamical systems is the use of cellular automata as simulation models. Such models are based on discrete mathematics. They enable relatively simple software implementations on modern supercomputers. Currently, there are no cellular automata models of electromagnetic waves that take into account such effects as reflection, refraction, diffraction, scattering, etc. The first step in developing such a model may be to build a prototype capable of simulating a two-dimensional space in which electromagnetic radiation propagates, with a set of different wave sources. A point monochromatic coherent directional source producing radiation in a selected direction can act as a basic element for the configuration of more complex types of emitters. By arranging such sources evenly along a straight line segment, it is possible to simulate a 2D variant of plane monochromatic electromagnetic wave. The paper presents a cellular automata model of a plane electromagnetic wave and its parallel software implementation. The results of computer experiments are presented, which show that the developed model corresponds to the physics of the propagation of electromagnetic waves in a homogeneous medium. A study of the performance of software implementation and the efficiency of parallelization was conducted.