A multi-function peripheral (MFP) including a machine body, a paper feeding cassette, and a sensing module is provided. The paper feeding cassette is assembled to the machine body, and multiple pieces of paper are suited for being stacked on a supporting surface of the paper feeding cassette. The sensing module includes a holder and a sensor. The holder is disposed at a side of the paper feeding cassette and capable of moving along a normal of the supporting surface. The sensor is disposed on the holder. A sensing surface of the sensor faces the supporting surface and keeps a distance from a top piece of the paper.