To reduce the dissipation of oil in a bearing device.

This bearing device 1 has a rotary shaft 2, and a sleeve 3 having a radial bearing surface 3a opposed to the outer peripheral surface 7 of the rotary shaft via a clearance 21 filled with liquid for supporting at least a radial load of the rotary shaft 2. The rotary shaft 2 has an annular step 8 of diametrally contracting the outer peripheral surface above the radial bearing surface 3a in the shaft direction. The step 8 is formed of first, second, and third outer peripheral surfaces 7a, 7b, and 7c on the rotary shaft 2. The first outer peripheral surface 7a is opposed to the radial bearing surface 3a. The second outer peripheral surface 7b is continuously formed on the first outer peripheral surface 7a, is exposed from the radial bearing surface 3a, and has the almost same outer diameter as that of the first outer peripheral surface 7a. The third outer peripheral surface 7c is continuously formed on the second outer peripheral surface 7b, is arranged on the opposite side of the first outer peripheral surface 7a with the second outer peripheral surface 7b between, and has an outer diameter smaller than that of the second outer peripheral surface 7b.