To provide a component built-in wiring board and a manufacturing method thereof capable of further improving component mounting density without deteriorating-reliability. The component built-in wiring board includes: a conductive layer (34, 35) extending in a thickness direction of the board and buried in the board without being exposed from an upper and a lower surface of the board; an electrical/electronic component (33) having a terminal and buried in the board with the terminal facing the buried conductive layer; a connecting member (36, 37) provided in a gap between the terminal of the buried electrical/electronic component and the conductive layer to electrically/mechanically connect the terminal and the conductive layer; and two upper and lower insulating layers (11, 15) which cover an outer surface of the buried electrical/electronic component excluding a portion connected to the connecting member and which are in close contact with a top and a bottom in the board thickness direction of the electrical/electronic component.