In one embodiment, the invention can be a touch input device capable of unlocking a passcode accordance with a touch pressure. The device can include a touch screen which displays a passcode input window; a controller which generates a first control signal as to whether or not a touch on the passcode input window matches a predetermined passcode; and a memory which stores the predetermined passcode. The passcode input window can include a plurality of nodes which are disposed in different positions. The number of touched nodes among the plurality of nodes, the order of the touched nodes among the plurality of nodes, and a pressure level of the touch on each of the touched nodes among the plurality of nodes can be set as the predetermined passcode. Further, the pressure level of the touch can he classified into at least two levels.