In a printed wiring board, an odd number (n) of conductive layers (11-13) and insulating layers (21-23) are alternately laminated upon another. The first conductive layer (11) is constituted as a parts connecting layer and the n-th conductive layer (13) is constituted as an external connecting layer which is connected to external connecting terminals (7). The second to (n−1)-th conductive layers (12) are constituted as current transmitting layers for transmitting internal currents. The surface of the n-th conductive layer (13) is coated with the outermost n-th insulating layer (23) in a state where the external connecting terminals (7) are exposed on the surface. It is preferable to constitute the initial insulating layers of a glass-cloth reinforced prepreg and the external insulating layers of a resin.