A portable electronic device. The portable electronic device includes a body, a cover, a button, a movable pin and a battery. The button is movably disposed on the body to move between a first position and a second position. The movable pin is disposed in the body. The battery is disposed on the body. When the button is in the first position, the cover is separated from the button. When the button moves from the first position to the second position, the movable pin pushes the battery, allowing the battery to be separated from the body.