To provide a practical bearing device highly excellent in cost effectiveness and workability.

The bearing device consists of a shaft 1; a cylindrical member 3, which is fitted to this shaft 1 via rollers; a pair of support bearing parts 4a, 4b, which are provided on the cylindrical member 3 and each comprise an inner ring part provided on the outside circumference of the cylindrical member 3 and an outer ring part arranged outside the inner ring part to support the rollers with the inner ring part; and an adjustment cylindrical member 12, whose outer cylindrical body is fitted and screwed to an inner cylindrical body provided between the pair of support bearing parts 4a, 4b. The adjustment cylindrical member 12 consists of the inner cylindrical body 8, on the outside circumferential surface of which a male thread part 9 is formed, and the outer cylindrical body 10, which is fitted to the inner cylindrical body 8 and on the inside circumferential surface of which a female thread part 11, which is screwed to the male thread part 9, is formed. It is structured to enable the outer ring parts 7a, 7b to be pressed in the direction of separating from each other and to release the pressing by adjusting the length in the axial direction by changing the screw length of the inner cylindrical body 8 and the outer one 10.