A dynamic pressure gas bearing motor in which a radial dynamic pressure gas bearing and a thrust dynamic pressure gas bearing are ensured to have sufficient length and diameter even though the clamping screw holes for introducing screws to reliably hold a disk are formed in the top wall of the motor rotation body. The top surface of the support shaft (2) has a downward recession, the motor rotation body (3) has a protruded part (3) facing the recession (2a) of the support shaft and fitted therein with clearance, a radial dynamic pressure gas bearing (6) is formed by the inner periphery of the motor rotation body and the outer periphery of the support shaft, a thrust dynamic pressure gas bearing (7) is formed by the protruded part of the motor rotation body and the recession of the support shaft, the thrust dynamic pressure gas bearing is provided below the top end of the radial dynamic pressure gas bearing, and clam screw holes (3c) for holding a disk are formed in the top wall of the motor rotation body above the recession of the support shaft.