Including a synthetic resin-made bearing base 2 having a base portion 4, an annular protruding portion 6 provided integrally on and protruding from one surface 5 of the base portion 4, and an air supply passage 11 which is provided in the annular protruding portion 6 and the base portion 4 and which has one end 7 open at a protruding end face 8 of the annular protruding portion 6 and another end 9 open at a outer peripheral surface 10 of the base portion 4; and a synthetic resin-made bearing body 3 having an annular recessed portion 42 which is formed in one surface 41 opposing the one surface 5 of the base portion 4 and which receives the annular protruding portion 6 of the bearing base 2, an annular recessed groove 44 which is open at another surface 43, and a plurality of air outlet holes 47 serving as inherent restrictors each of which communicates with the annular recessed groove 44 at one end 45 and opens to the annular recessed portion 42 at another end 46.