A device correcting a power factor caused by an input current delay of a three-phase inverter and a method of controlling the same are disclosed. In case of a product having a high-current power environment and a high-capacity inverter, a three-phase power factor correction (PFC) device detects any erroneous PFC operation of the three-phase inverter using a current sensor located at a common potential terminal. So, if the input current delay occurs, the three-phase PFC device delays an ON time of a switching element from a zero-crossing point of the input voltage, and performs an optimum switching operation caused by the input-current delay, resulting in the implementation of an increased power factor.