The present invention provides an etching composition, comprising a silyl phosphate compound, phosphoric acid and deionized water, and a method for fabricating a semiconductor, which includes an etching process employing the etching composition. The etching composition of the invention shows a high etching selectivity for a nitride film with respect to an oxide film. Thus, when the etching composition of the present invention is used to remove a nitride film, the effective field oxide height (EEH) may be easily controlled by controlling the etch rate of the oxide film. In addition, the deterioration in electrical characteristics caused by damage to an oxide film or etching of the oxide film may be prevented, and particle generation may be prevented, thereby ensuring the stability and reliability of the etching process.