Aerogel composite, support material with aerogel composite, and heat-insulating material

Provided is an aerogel composite that is the dried product of a wet gel that is a condensate of a sol containing silica particles, which have 10×10 18 to 1000×10 18 silanol groups per gram, and at least one substance selected from the group consisting of: silicon compounds having a hydrolysable functional group or a condensable functional group; and hydrolysates of silicon compounds having said hydrolysable functional group.