Disclosed is a capacitor for a semiconductor device, comprising: a lower electrode formed over a predetermined lower structure on a semiconductor substrate; an aluminum oxynitride film formed over the lower electrode and having a low leakage current characteristic; a yttrium oxynitride film formed over the aluminum oxynitride film and having a higher dielectric constant than the aluminum oxynitride film; and an upper electrode formed over the yttrium oxynitride film, and a manufacturing method thereof.