The present invention aims to achieve a reduction in cost for a fluid dynamic bearing device. The fluid dynamic bearing device supports a shaft member (2) radially in a non-contact fashion by a dynamic pressure action generated in a radial bearing gap between an outer peripheral surface of the shaft member (2) and an inner peripheral surface (7a) of a bearing member (7), and is composed of the shaft member (2), the bearing member (7), a cover member (8), and a seal member (9). The shaft member (2) is inserted into an inner periphery of the bearing member (7), and an opening at a lower end thereof is sealed by the cover member (8). The seal member (9) is attached to an opening at an upper end of the bearing member (7), forming a seal space (S) between itself and the outer peripheral surface of the shaft member (2). Dynamic pressure grooves (G) of radial bearing portions (R1 and R2) are formed in an inner peripheral surface (7a) of the bearing member (7) by molding.