Provided are a dielectric monolayer thin film, a capacitor and a semiconductor device each including the dielectric monolayer thin film, and a method of forming the dielectric monolayer thin film, the dielectric monolayer thin film including an oxide which is represented by Formula 1 and has a perovskite-type crystal structure, wherein the oxide has a surface chemically bonded with hydrogen.

A2Bn−3CnO3n+1  



wherein, in Formula 1, A is a divalent element,
B is a monovalent element,
C is a pentavalent element, and
n is a number from 3 to 8.