A power plane includes a first circuit region and a second circuit region. The length of the first circuit region or second circuit region is related to the noise frequency to be filtered out. The width of the first circuit region can be wider or narrower than the width of the second circuit region. While manufacturing the power plane, a predetermined length is decided according to the resonance frequency of an original power plane, then the proposed power plane is formed with the first circuit region and the second circuit region of a predetermined length, and making the width of the first circuit region wider or narrower than the width of the second circuit region, such that the noises with the resonance frequency can be mitigated.