A method for operating a function in a touch device capable of simultaneously changing an option and executing the function based on an input touch event during execution of a function using a function button provided in a certain mode which is executed in a touch device supporting touch based input and an apparatus thereof is provided. The method includes executing a second function associated with option setting according to a touch event input to a function button; and executing a first function allocated to the function button according to an option value set by the second function when the input touch event is released.