Along with the increasing level of criminal data theft that occurs, a good room security system is needed to maintain data security of a particular agency or organization. A good security system is a security system that can be monitored and controlled over long distances using the internet or better known as IoT (Internet of Things). In this thesis, an IoT-based room security system will be designed using an Android application, this system works using several modules including RFID (Radio Frequency Identification) module, camera module and solenoid door lock. RFID cards in the RFID Module function as a process of identifying people who want to enter the room. In addition, this RFID module functions also as a trigger for the camera to work and taking pictures of people who want to enter the room. Data obtained from both modules will be sent to the Android application. The admin of the room can carry out a verification process to allow or reject the person who wants to enter the room. The results of the testing of this system can run well when the internet speed of the access point runs fast and stable, but it is less optimal when the internet speed of the access point runs slowly.