Abstract: A ventilated disc rotor includes a hat portion at which the ventilated disc rotor is attached to a rotation shaft, a sliding portion formed in an annular shape and provided at a radially outer portion of the hat portion, the ventilated disc rotor being slidably held by an inner pad and an outer pad at the sliding portion so as to brake a rotation of the ventilated disc rotor and the sliding portion including an inner disc-shaped portion, an outer disc-shaped portion and a plurality of cooling fins, wherein the hat portion and the plurality of cooling fins are integrally made of a steel plate material, and the outer disc-shaped portion and the inner disc-shaped portion are formed by casting together with the plurality of cooling fins in such a way that the plurality of cooling fins integrally connects the inner disc-shaped portion to the outer disc-shaped portion.