A motor (100) having a dynamic pressure fluid bearing is composed of a hub (2), a rotor (4) provided with a shaft (7) of which one end portion is securely fastened by the hub (2) and another end portion is formed with a flange (8), and a stator (3) composed of a sleeve section (9) for axially sustaining the shaft (7) so as to be rotatable freely and a thrust plate (10) secured on the sleeve section (9) so as to confront with the flange (8), wherein the dynamic pressure fluid bearing is composed of a thrust dynamic pressure fluid bearing constituted by the flange (8) and the thrust plate (10), and wherein the shaft (7) is provided with a through hole (17) bored through the shaft (7) from the one end surface to the other end surface, and wherein the through hole (17) is formed in a shape having an opening to the other end surface of the shaft (7) by way of a funnel shaped section (17c) of which diameter gradually increases toward the other end surface of the shaft (7).