Wiring board

A wiring board comprising:

• a core insulating layer;
• a first laminated body located on an upper surface of the core insulating layer;
• and
• a second laminated body located on a lower surface of the core insulating layer, wherein
• each of the first laminated body and the second laminated body has a structure in which at least four electrical conductor layers and at least three build-up insulating layers are alternately located,
• the first laminated body comprises a first mounting region configured to mount electronic components,
• the electrical conductor layers comprise at least two types being a first electrical conductor layer having a first electrical potential and a second electrical conductor layer having a second electrical potential that is different than the first electrical potential, and
• in the electrical conductor layers in the first laminated body:
• at least a first outermost layer and a first innermost layer are the first electrical conductor layers, and
• a first intermediate layer located farther from the core insulating layer than the first innermost layer comprises at least two or more of the second electrical conductor layers having the second electrical potential and disposed consecutively with a build-up insulating layer between consecutive second conductor layers.