A lenticular capsule-expanding device is arranged in a lens capsule in a cataract surgery, etc. The device includes a front supporting section to be arranged in contact with an inner surface of an anterior capsule, the front supporting section, a rear supporting section to be arranged in contact with an inner surface of a posterior capsule, the rear supporting section being arranged behind the front supporting section, and a connecting section that connects the front and rear supporting sections in a manner as to have an urging force for separating the front and rear supporting sections in a separating direction. By the urging force of the connecting section, the front supporting section presses against the inner surface of the anterior capsule and the rear supporting section presses against the inner surface of the posterior capsule.
