A feeding device is disclosed, which comprises a paper passage, a sheet-separating roller, a friction institution, and a stopper. The sheet-separating roller is disposed in the paper passage. The friction institution is disposed in the paper passage opposite to the sheet-separating roller. The stopper is disposed in the upstream side of the sheet-separating roller. The stopper includes an axle, a short arm, and a long arm. The short arm connects to the axle, and the axle acts as a fulcrum. The long arm and the short arm disposed to the axle coaxially. A threshold of the force for pushing the short arm is larger than a threshold of the force for pushing the long arm.