The purpose of this system is to develop AVR microcontroller based temperature control system with real time data logger. The temperature monitoring and controlling is becoming more crucial issue in today's word it also having a more importance in a various industry & various processing plants. Proposed system consists of design and construction of an AVR microcontroller-based automated Temperature control system & data logging. A data logger keeps the record of temperature measurements over a period of time. Data loggers are provided with real time clocks where data is sequentially stored in memory.