An accommodative intraocular lens capable of effectively exerting a focus adjustment function includes an optical portion and a plurality of support portions arranged around the optical portion. The support portion includes an anterior support portion and a posterior support portion, and the anterior support portion presses an anterior capsule and the posterior support portion presses a posterior capsule by the elastic force of the support portion. When the lens capsule is in a distance vision state or in a near vision state, as the pressing force of the anterior capsule against the anterior support portion increases or decreases, the anterior support portion deflects backward or returns forward while maintaining the radial position of the base end portion, so that the tip end portion of the anterior support portion moves backward or forward greatly while maintaining the radial position, and the optical portion moves backward or forward accordingly.