The research topic is aimed at solving the problem of achieving the stable development of society, so it is relevant. The problem is that, according to the existing axiom of the economy, the material needs of a man are limitless. Thus, this axiom justifies and stimulates the pursuit of enrichment, which is achieved even by breaking laws. An insatiable effort to be financially successful has led to inequalities between people and countries. In spite of all the efforts, inequality is increasing rapidly. The question is, what pleasure does a person enjoy in achieving material goals? The study of human satisfaction with material benefits has been widely reported in the literature, however, a mathematical model of human satisfaction with material goods and a unit of satisfaction has not been developed. The absence of a mathematical model makes it impossible to find out the regularities of this phenomenon - human satisfaction in the process of obtaining material goods. The paper hypothesizes that the law of human satisfaction with material goods is expressed by a logarithmic function, which is shifted along the abscissa axis so that at zero abscissa the function equals zero. A unit of satisfaction, called comfort, has been introduced. The feeling of satisfaction is expressed as the first derivative of the logarithmic function. It is known that this function approaches zero as the argument grows. The introduction of the human satisfaction law from material goods in the form of a mathematical model gives grounds to make fundamental conclusions. Since the increase in satisfaction with the increase in material goods is slowing down, and the feeling of satisfaction in general approaches zero, it is not necessary to follow the basic axiom of the economy of a capitalist society and spend exertion to satisfy material needs, especially since the feelings of it will become zero. Scientific research proves that a person is able to absorb new ideas, able to learn and apply the acquired knowledge in everyday life. This gives confidence that due to the qualitative motivational implementation of the proposed law, people will realize it as a personal life strategy, and the development of society will become more stable

material satisfaction; law of material satisfaction; factors of sustainable development; happiness index