The air blower includes a case body having an air suction mouth and an outlet formed at a peripheral wall thereof; a motor which is installed into the case body, having a fluid dynamic bearing; and an impeller which is fixed to a rotation member of the motor, having a plurality of blade support plates, which is formed in the shape of a ring, capable of suctioning air from the air suction mouth by rotating and discharging from the outlet, provided at an upper and lower surfaces thereof, equalizing the difference in pressure between the upper and lower surfaces thereof. Therefore, it can rotate at a high speed, blow in under high pressure at large air volume even though it has small size and is economical and long-lived.