Wiring substrate and method for manufacturing the same

A method for manufacturing a wiring substrate, comprising:

• forming, on a support member, a plurality of insulating layers including a first insulating layer and an outermost insulating layer such that the first insulating layer is positioned at one end of the plurality of insulating layers in a lamination direction and that the outermost insulating layer is positioned at an opposite end of the plurality of insulating layers in the lamination direction and comprises a reinforcing material, and a plurality of conductive layers laminated on the insulating layers such that the plurality of conductive layers includes an outermost conductive layer formed on the outermost insulating layer and comprising a plurality of pads;
• and
• removing the support member from the insulating and conductive layers,
• wherein the forming of the insulation and conductive layers comprises forming the first conductive layer on the support member, forming the accommodating portion in the first insulating layer such that the accommodating portion penetrates through the first insulating layer, accommodating a semiconductor element in the accommodating portion of the first insulating layer such that the semiconductor element is positioned in the accommodating portion of the first insulating layer, forming the outermost insulating layer at the opposite end of the plurality of insulating layers in the lamination direction, and forming the outermost conductive layer on the outermost insulating layer such that the outermost conductive layer comprises the plurality of pads, the removing of the support member comprises removing the support member from the first insulating layer such that the semiconductor element is accommodated in the accommodating portion of the first insulating layer before the support member is removed from the first insulating layer, and the plurality of insulating layers is formed such that the insulating layers do not contain a reinforcing material other than the outermost insulating layer.