To prevent or suppress a failure of a tire bead core due to the separation of coated rubber on a pneumatic tire from steel wires, a tire bead core (6) of a green tire (1) is provided with a pluralityof bead steel wires (8) in the cross section in the width direction of the tire bead core (6), and arranged apart in the width direction and radial direction of the tire bead core (6); coated rubber (9) filling the space among the bead steel wires (8). The ratio of the area of the coated rubber (9) in the cross section in the width direction of the tire bead core (6), relative to the area of the cross section of an outline (6a) of the tire bead core (6), namely the area of the cross section of the tire bead core, is 65% or above and 75% or below.