In this paper, the design and development of a low-cost monitoring system is reported, in order to control the critical operating parameters of a data center, such as temperatures in the most representative spots of the server room, the cooling system efficiency, power supply related physical measurables useful to evaluate its quality and efficiency level. This solution, specifically customized for the new data center of the Italian National Data Center (IT-NDC) located at the Roma 2 branch office, is actually designed with a modular structure, where hardware and software components can be easily added, even to detect parameters not explicitly planned in this specific work.