Disclosed is an uninterruptible power supply including a switch connected between an external power source and a load, a power supply module connected to the external power source and the switch for receiving and converting an input power and supplying converted power to the load, a battery module connected to the power supply module for storing electric power or supplying electric power to the power supply module, a control module connected to the external power source and the battery module and powered by the external power source or the battery module for generating a control signal according to a specific operating status of the power supply module to manipulate the switch so as to supply power to the load through the power supply module or a bypass route, and a display panel connected to and powered through the control module for receiving and displaying system status information from the control module.