To prevent
static electricity from entering a ground region on which a connector is mounted.SOLUTION: A front layer of a
printed circuit board 100 includes: frame ground regions 102a, 102b on which connectors 202, 203 to be connected with external apparatuses or communication cables are mounted and which are connected with a ground; a
signal ground region 101 which is separated from the frame ground regions 102a, 102b at the front layer, on which electronic devices 200, 201 configured to receive signals from the connectors 202, 203 are mounted, and which is connected with the ground; and a
static electricity removal ground region 103 separated from the frame ground regions 102a, 102b and the
signal ground region 101 at the front layer, situated outside the frame ground regions 102a, 102b, and connected with the ground.SELECTED DRAWING: Figure 3