A thick conductor built-in type printed wiring board includes a printed wiring board, an insulating resin layer, an insulating base material layer, and a conductor layer. The printed wiring board includes an insulating layer including a cured product of a first resin composition, and a circuit provided on one main surface or both main surfaces of the insulating layer, the circuit having a plurality of conductor wirings each having a thickness ranging from 105 μm to 630 μm, inclusive. The insulating resin layer covers a surface of the printed wiring board on which the circuit is provided, and includes a cured product of a second resin composition and includes no fibrous base material. The insulating base material layer covers the insulating resin layer, and includes a cured product of a third resin composition and a fibrous base material. The conductor layer covers the insulating base material layer. The thick conductor built-in type printed wiring board does not include a void having a diameter of more than or equal to 10 μm inside the thick conductor built-in type printed wiring board.