A control method for providing a partial lock function in a portable device having a touch input unit and a lock key is provided. The control method includes entering a first lock state; determining whether an input of the lock key is received; determining, if an input of the lock key is received, which one of a second lock state and a third lock state is selected; and setting a lock state of the portable device to the selected lock state. Each of the first, second and third lock states is different from the other two lock states and is one of an entire lock state, a partial lock state and an entire unlock state. The input means may be a touchpad, a touchscreen and an optical jog, and at least one input manner is a touch or a sweep. The partial lock state may be a state in which a lock and an unlock function are provided according to the types or input manners of the touch input unit.