A static random-access memory structure includes a substrate, a first conductive type transistor, a second conductive type transistor and a capacitor unit. The first conductive type transistor and the second conductive type transistor are disposed on the surface of the substrate, and the capacitor unit is positioned between the transistors. The capacitor unit includes a first electrode, a second electrode, and a dielectric layer disposed between the first electrode and the second electrode. The first electrode includes a plurality of first protrudent portions and a planar portion. The first protrudent portions are connected to the first planar portion and protrude from the top surface of the planar portion. The second electrode covers the top surface of the first protrudent portions and formed between adjacent first protrudent portions.