To provide an oil-impregnated sintered bearing in which oil leakage from the outer circumferential surface can be prevented.

In the oil-impregnated sintered bearing 1 in which a bearing hole 3 with a rotary shaft inserted therethrough is formed in a bearing body 2 formed of a porous sintered alloy including air holes inside, an air hole opened on the outer circumferential surface of the bearing body 2 is crushed. Air holes may be crushed in a compact or air holes may be crushed in a sintered alloy made by sintering a compact. Thereby, lubricating oil does not leak from the outer circumferential surface 7 of the bearing 1, and hydraulic pressure in the bearing hole 3 in the inside can be secured. Further, the inner circumferential surface of an attachment part 41 is formed in a polygon, and the bearing body 2 is fitted and fixed by press-fitting. Meanwhile, a gap is produced between the outer circumferential surface 7 of the bearing body 2 and the inner circumferential surface of the attachment part 41.