Abstract: In an image sensing apparatus, by forming a signal processing unit which processes a signal from an image sensing unit on an expansion board of a computer or a PCMCIA card, it is possible to easily control the image sensing unit, process a signal from the computer, and by taking an image signal into an image processing unit immediately, reduces deterioration of the signal. Further, the image sensing unit is separated from the signal processing unit, and data specific to the image sensing unit is processed by the signal processing unit, thereby various types of image sensing units can be controlled.