Power management is the feature available in most of the embedded systems and some other electrical or electronics units, like display of a mobile handset or monitor of a personal computer, which automatically turns off the device or put it in low powered stand-by mode for power saving. This mechanism not only prolongs the battery life of portable units but also reduces the heat dissipation, which prolongs the life of the machine, reduces the maintenance overhead, as less cooling is necessary, and also protects the environment. With the increasing use of microcontrollers in all sorts of applications, low power has become an very important parameter when designing microcontroller based system. Today’s microcontroller designs are often battery or signal wire powered applications replacing passive or mechanical components. Common for them all is the requirement of very low power consumption but with enough power to fill the specification of the product. The project presented here is uses power management feature of 8051 microcontroller which automatically turns off the device or put in mow powered standby mode for power saving. This mechanism not only prolongs the battery life of portable units but also reduces the heat dissipation, which prolongs the life of system, reduces the maintenance overheads, as less cooling is necessary, and also protects the environments.