To provide a ceramic made dynamic-pressure bearing capable of preventing breakage of ceramics by preventing the occurrence of linking and seizing, and effecting stable rotation.

A gas dynamic-pressure has structure that a bearing part provided with an inner cylinder 15 being a fixed part and an outer cylinder 7 being a rotation part is nipped by two thrust plates 21 and 23 and is that the inner cylinder 15 , the outer cylinder 7, and the thrust plates 21 and 23 are formed of ceramics. Flatness of dynamic pressure generating parts 7a and 7b being the two end faces in a vertical direction of the outer cylinder 7 is set to a range of 3 μm or less, and flatness of a lower end face dynamic pressure generating part 21a of the upper thrust plate 21 and an upper end face dynamic pressure generating part 23b of the lower thrust plate 23 is also set to a range of 3 μm or less. Further, at upper and lower end face dynamic pressure generating parts 7a and 7b of the outer cylinder 7, flatness thereof exceeds 0 μm and is increased to a range of 2.5 μm or less. Meanwhile, the two thrust plates 21 and 23 are a flat plate and there if no difference in height between an inner peripheral part and an outermost peripheral part.