A metal-insulator-metal (MIM) capacitor structure and a method for forming the same are provided. The MIM capacitor structure includes a substrate, and the substrate includes a capacitor region and a non-capacitor region. The MIM capacitor structure includes a first electrode layer formed over the substrate, and a first spacer formed on a sidewall of the first electrode layer. The MIM capacitor structure includes a first dielectric layer formed on the first spacers, and a second electrode layer formed on the first dielectric layer. The second electrode layer extends from the capacitor region to the non-capacitor region, and the second electrode layer extends beyond an outer sidewall of the first spacer.