This paper presents the administrative system developed in Can Tho University (CTU) to manage the usage of class rooms for students in self-study time. The motivation of this research derived from several practical requirements. Firstly, empty lecture rooms in CTU during weekdays are numerous, and the needs of booking these rooms for team-working and group projects are also plenty. However, students encounter many difficulties to register traditionally to these rooms by coming directly to the administrator of the buildings. Meanwhile, the building managers are also facing troubles in managing identities of students who would use the rooms; the electricity waste when nobody is inside a room as well as the responsibility for missing or broken valuable facilities of the classroom such as projectors and multimedia device are also a huge problem in the university. This IoT-based system contains two main parts: a hardware device and a web-based server. The hardware is developed on a ESP32 microcontroller platform with the deployment of 2 individual cores inside the microcontroller. It will connect to the internet using MQTT protocol via cloudmqtt.com free broker. Classrooms can be booked indirectly through the web server or directly by interacting the ID card of users with a 125Khz RFID reader integrated in the hardware device. The device is placed onto the wall, next to the main Circuit Breaker of each room. The web server is mainly written in python and Django framework, provides the ability to monitor the room status in real time beside the ability to register to an empty room. The users’ ID and users’ activities will be stored in a database, which can be extracted easily by the administrator of the building through an admin account.