The development of science and technology has been increasing rapidly, providing convenience in everyday life. Various household appliances and office work tools use electronic devices to ease the works, including bell warning systems for prayer times. The system notifies the people when the times for prayer comes. The warning systems used presently have not operated automatically. The research aimed to design and implement a series of automatic warning bell system for prayer times, that sent a notification to the telegram. It used Arduino Mega 2560 as the data processor. The result found that the tool, equipped with an RTC, a Dfplayer, a loud-speaker, and an Ethernet Shield, worked satisfactorily by sending a notification to the Telegram.