A power management apparatus includes an electric device including a plurality of operation algorithm information and power information for each operation level corresponding to each operation algorithm information, and a power management unit to receive power rate information from a power provider, determine an operation level of the electric device on the basis of the received power rate information and power information for each operation level of the electric device, and control an operation of the electric device at the determined operation level. As a result, the power management apparatus performs different operation algorithms according to power rate information, and controls power consumption of the electric device, such that energy efficiency at the user side can be maximized. In response to the changed power rate information, the currently-driven electric device and the electric device to be driven can be driven at the optimum operation level appropriate for their power consumption characteristics.