A component built-in wiring board is provided. The component built-in wiring board 10 includes a core substrate 11, a first component 61, a first built-up layer 31 and a capacitor 101. The core substrate 11 has a housing hole 90 and the first component 61 is housed in the housing hole 90. A component mounting region 20 capable of mounting a second component 21 is provided in a surface 39 of the first built-up layer 31. The capacitor 101 has electrode layers 102 and 103 and a dielectric layer 104. The capacitor 101 is embedded in the first built-up layer 31 such that a first front surface 105 and a second front surface 106 in the electrode layer 102 and a first front surface 107 and a second front surface 108 in the electrode layer 103 are disposed in parallel with the surface 39 of the first built-up layer 31.