In a floating unit, a floating mechanism is provided with: a rolling portion that includes a holding portion fixed to one of a first member and a second member, a sphere held by the holding portion so as to be rotatable in all directions; and an opposing portion that is fixed to the other one of the first member and the second member, and has an abutment surface that abuts against the sphere. The abutment surface includes an inclined surface that is formed, over the entire region of the abutment surface in a circumferential direction around a reference position, so as to come close to a side, in the vertical direction, on which the sphere is arranged, while extending outward in the horizontal direction from the reference position.