Recent years have been characterized by the rapid development of Internet of Things (IoT) and edge device technologies. Systems of various purposes with IoT elements and edge devices are increasingly finding practical use in people’s lives, the IoT element base is expanding and improving, which makes it possible to develop effective measuring systems, including those with feedback control. An essential role in ensuring people’s lives is played by the microclimate of the premises where people live, work, and study. As you know, the excess or decrease of the environmental microclimate relative to the norm negatively affects the physiological state of a person, his performance, and concentration and reduces the efficiency of work and training. Therefore, in this work, the problem of round-the-clock monitoring of the microclimate of classrooms is solved by developing an autonomous IoT system using edge devices to measure climatic parameters such as temperature, relative humidity, carbon dioxide level in the air, and the concentration of light air ions with data recording on a smartphone and saving on a remote server. The principles of building microclimate monitoring systems are presented, the requirements for the system are set, the criteria for choosing the elemental base and the technical characteristics of each component are given. The structure of the air ion concentration sensor developed by the author and the method of measuring the air ion concentration in the room are also described. The structural diagram of the developed microclimate parameters monitoring system is also presented. The development is part of a system for studying the influence of microclimate parameters on the physiological state of applicants for education. The results obtained in the work will allow development measures to ensure the necessary normal conditions for training in confined spaces. Research conducted using the developed system will allow better formation of student learning conditions in order to achieve maximum performance indicators.