Mobile apparatus having joystick button

A mobile apparatus is proposed. A display unit is disposed at a front side of the mobile apparatus. A joystick button is disposed at a back side opposite to the display unit. A pressure sensing unit detects a pressing and rotating operation and a pressure value applied to the joystick button. When the mobile apparatus is waked up from a power-saving mode, a controlling module controls the display unit to display an unlocking screen which includes icons corresponding to directions of the joystick button. When the display unit displays the unlocking screen, a detecting module detects at least one first pressing and rotating operation applied to the joystick button. When an unlocking combination of the at least one first pressing and rotating operation matches an unlocking pattern, an unlocking module unlocks the mobile apparatus.