A circuit wiring board including a wiring substrate, multiple electronic components provided on a surface of the wiring substrate, and a heat resistant substrate accommodated in the wiring substrate and having a core substrate and a built-up wiring layer formed over the core substrate. The built-up wiring layer includes a conductive layer and an interlayer resin insulating layer, and the electronic components are electrically connected to the conductive layer of the built-up wiring layer.