An outer peripheral surface (8d) of a bearing sleeve (8) is formed on a radially inside with respect to a first dynamic pressure generation portion (B1). In this case, it is possible to reduce a thickness of the bearing sleeve (8) while securing a first thrust dynamic pressure generating portion (B1) which has a thrust load capacity equivalent to that in a conventional case where a thrust dynamic pressure generating portion is formed in an end surface of the bearing sleeve. Accordingly, it is possible to reduce the thickness of the bearing sleeve (8) without sacrificing a bearing performance in a thrust direction. With this structure, a total amount of a lubricating oil sealed in a bearing device can be reduced, thereby reducing a capacity of a buffering function so as to downsize a sealing portion (9), and by extension, downsizing a fluid dynamic bearing device (1).