A printed circuit board (PCB) can prevent electrostatic discharge. A number of vias are embedded in the PCB. A circular insulated member is disposed between each via and the number of vias. Each via includes a layer of metal coated on an inner wall of a corresponding insulated member and a through hole bounded by the corresponding insulated member. An acute angle between two tangents which pass through a point of intersection of two overlapped insulated members is greater than twenty degrees.