To provide a bed apparatus capable of solving low usability associated with the prior bed apparatus, such as a user feels pressure or the body of the user moves forward when raising the back, and also capable of preventing a person to be cared from falling down from the bed by using a side slip preventing function.

The surface of the bed apparatus is divided into a plurality of bed faces. The bed apparatus is configured such that the posture of the user can be changed from a supine position to a sitting position or from the sitting position to the supine position by moving each of the bed faces. When changing the posture from the supine position to the sitting position, the bed face 4 corresponding to the buttocks sinks a predetermined amount so that the angle of the pelvis has a predetermined angle of α.