In general, a smart card is an integrated circuit card with memory capable of making decisions. A smart card, chip card or integrated circuit card (ICC), is defined as any pocket-sized card with embedded integrated circuits which can process information. In this project, we are using a contact smart card where the information inside the card is communicated with the card reader by inserting card into the card reader. The card reader in this project used is an SR-90 SDK of 1KB memory size. The Smart Card Reader is an electronic device that reads smart cards. The card reader supplies the integrated circuit on the smart card with electricity. The main objective of this project is Authenticated device control system which is implemented using smart card. This project is designed around a Microcontroller which forms the Control unit of the project. A smart card is used as an authentication for device control. According to this project the person who wants to access a device needs to carry his Smart Card with him. Whenever he wants to access the device, he needs to insert his smart card into the smart card Reader. The project is designed in such a way that the controller will be interfaced to the smart card reader through a line driver IC max232 for serial communication. In this project 7805 is a regulator and it avoids noise spikes in power supply. SMART card modem is connected microcontroller through serial port. These SMART card modem works under 9600 or 4800 baud rates.