Present paper considers a structure model of discrete space-time, the properties of which are determined by the substrate. As a substrate a 2-dimensional plane under no matter is chosen, the surfaces of which are space and anti-space.A new concept called spacetron, considered as a spatial element of the substrate, which is the basis for the subsequent formation of 4-dimensional space-time, is proposed. Upper-level spacetrons are a hexagonal 2-dimensional packing, with spacetrons of other levels (first, second, etc.) placed between them, followed by their identification with electron-positron pairs, neutrinos and electromagnetic field quanta. It is shown how the connectivity of space-time is determined by completely filling the substrate space with spacestrons of different sizes, which allows us to consider the resulting 4-dimensional space-time as a quasi-continuous medium. It is shown that in the case of contact interaction of space-time substrate spacestrons, all of them can be given a spherical shape by partitioning the upper level spacestrons into linked objects, called a loveton, which is a three-dimensional object, and an anti-loveton, which is an anti-space object.Within the framework of the computer model the mechanism of the appearance of matter in space-time is considered. The appearance of matter takes place under the influence of energy perturbations of space-time structural elements, causing the appearance of both free lovetons (anti-lovetons) and other material objects. Based on the analysis of the geometric position and dimensions of the substrate features responsible for the formation of elementary particles and the electromagnetic field quantum spectrum, the estimated masses of a number of elementary particles are determined and the known particle masses are assigned to them. The masses of free lovetons and neutrinos are evaluated on the basis of geometric relations between the sizes of particles on the basis of electron masses. At least three varieties of neutrinos, which can be regarded as types of high-energy γ-quanta, are identified.The results of the work are valid and reliable because they are based on known approaches of relativity theory and quantum physics, as well as on the application of approximations adequate to the phenomena under study.