The present invention relates to a light-controlling element comprising a polymer gel composition layer containing: a holding member; liquid held by the holding member; and a stimulus-responsive polymer gel which is held by the holding member and which changes in volume by absorbing or discharging the liquid due to an external stimulus, wherein the stimulus-responsive polymer gel is arranged in a single layer in the holding member, and also relates to a method for manufacturing the element. The polymer gel composition layer can be provided with a substrate on one side or both sides thereof, and further can be provided with a stimulus providing member.