Disclosed is a method of manufacturing a storage capacitor having increased aperture ratio: providing a substrate having a metal layer disposed thereon, and said metal layer is covered correspondingly with a first dielectric layer and a second dielectric layer in sequence; forming a photoresist layer with a uniform thickness to cover said second dielectric layer; performing a process of exposure-to-light and development to a portion of said photoresist layer that is correspondingly disposed over said metal layer sequentially, so that its thickness is less than its original thickness; removing said photoresist layer and etching said portion of said second dielectric layer, so that a thickness of said portion of said second dielectric layer is less than its original thickness, and the etching depth of said portion is greater than that of the other remaining portions of said second dielectric layer; and forming an electrode layer on said second dielectric layer.