To facilitate application for existing beds by a method wherein a slider with the lower end of leg parts securely placed thereon is placed on a base member set on a floor and reciprocated by a drive part across the width of the bed in the device which oscillates a bed where a high-aged person is laid.

This oscillating device 1 of a bed is constituted of a pair of base members 10 and 10 installed on a floor, a slider 20 which has leg parts 41 of a bed 40 fixed thereon and is reciprocated on the base member 10 across the width of the bed 40 and a drive part 30 to reciprocate the slider. The spider 20 is made up of a rack gear 22 installed on a base plate and a pinion shaft in which a pinion gear 23 meshed with the rack gear 22 is fixed on both end sides thereof. The drive part 30 has a rotating shaft of a motor 31 linked to the base plate through a link 32. A base end part of the link 32 is driven in a roughly oval track to reciprocate the base plate (slider 20) thereby oscillating an aged person or the like lying on the bed.