Disclosed are a capacitor for semiconductor devices capable of increasing storage capacitance and preventing leakage current, and method of manufacturing the same. The capacitor for semiconductor memory devices according to the present invention includes: a lower electrode; a dielectric layer formed on the lower electrode; and an upper electrode formed on the upper portion of the dielectric layer, wherein the dielectric layer is a crystalline TaxOyNz layer, and the total of x, y, and z in the crystalline TaxOyNz layer is 1, and y is 0.3 to 0.5, and z is 0.1 to 0.3.