A method and device for releasing a lock function of an input device of a mobile terminal are provided. The method of releasing a lock function of an input device of a mobile terminal includes detecting a user's input, determining whether the lock function of the input device is set, displaying, if it is determined that the lock function of the input device is set, display data representing that the input device is in a locked state and displaying function data of a function to be entered upon release of the lock function of the input device, and entering, immediately upon performance of a preset lock release operation, a specific function corresponding to the function data.