A wireless input device integrable with a mobile device which includes a wireless keyboard, a carrier and a retracting plate. The wireless keyboard has a top surface provided with a plurality of keys and two opposite sides each provided with a first rail element. The carrier has a top surface concavely provided with a receiving cavity so that the mobile device can be placed and secured in position in the receiving cavity. The retracting plate is movably embedded in a bottom surface of the carrier, and provided with a second rail element at each of two opposite positions for engaging with the first rail elements respectively, so that both the carrier and retracting plate are movable along the rail elements to a position where the wireless keyboard is completely covered by the carrier or where all the keys are exposed outside the carrier.