A printed wiring board including solder pads excellent in frequency characteristic is provided. To do so, each solder pad 73 is formed by providing a single tin layer 74 on a conductor circuit 158 or a via 160. Therefore, a signal propagation rate can be increased, as compared with a printed wiring board of the prior art on which two metal layers are formed. In addition, due to lack of nickel layers, manufacturing cost can be decreased and electric characteristics can be enhanced.