Provided are a circuit board which meets requirement of suppressing peeling of a through hole conductor, a mounting structure and a method for manufacturing the circuit board. A circuit board (2) is provided with a base (5) and a through hole conductor (11). The base is provided with a fiber layer (9) and a through hole (S). The fiber layer has a single fiber (8) arranged along one direction and a resin for covering the single fiber (8). The through hole (S) penetrates the fiber layer (9), and the through hole conductor is formed in the through hole. The single fiber (8) partially protrudes to the side of the through hole conductor (11) from an inner wall surface of the through hole (S), and the protruded part is covered with the through hole conductor (11).