A camera module is provided. The camera module comprises: a lens; a holder having a lower portion, the holder holding the lens; a circuit board; and an image sensing and processing unit including an image sensing device and an optional signal processing device stacked on and electrically connected to the image sensing device, the image sensing and processing unit being packaged on one side of the circuit board; wherein the holder is fixed on the circuit board, the image sensing and processing unit inside the lower portion of the holder. Further, if the circuit board is a flexible circuit board, then a hard plate can be disposed on the other side of the flexible PCB corresponding to the image sensing and processing unit in order to enhance the mechanical strength.