A fluid dynamic pressure bearing has an annular dynamic pressure generating face having a dynamic pressure generating groove, which draws a working fluid toward a midway position in the radial direction from the inside and outside of a thrust bearing plate in the radial direction when a shaft and a housing are rotated relative to each other. The dynamic pressure generating groove is provided on thickness direction end faces of the thrust bearing plate or on an inner surface of the housing, and an inner groove section is located on an inner peripheral side of the dynamic pressure generating face on the end faces and is recessed more than the dynamic pressure generating face in the thickness direction. A through-hole extends through the thrust bearing plate in the thickness direction so as to open to the dynamic pressure generating face, and a communicating cavity connects the opening portion of the through-hole and the inner groove section.