A method of producing compounds which comprises the steps of separately vaporizing a plurality of substances containing the component elements of a desired compound and placed in a plurality of crucibles to form vapors of the substances, mixing the vapors in a heated mixing chamber to form a mixed vapor, jetting the mixed vapor into a vacuum region to form clusters, ionizing the clusters to form cluster ions, and accelerating the cluster ions to make them impinge on a substrate.An apparatus for producing compounds which comprises a plurality of crucibles for separately vaporizing substances containing the component elements of a desired compound to form vapors of the substances, a mixing chamber for heating and mixing the vapors introduced therein to form a mixed vapor, the mixing chamber having at least one injection hole for jetting the mixed vapor into a vacuum region, communication pipes for connecting the mixing chamber to the crucibles, an ionization chamber for ionizing clusters produced from the mixed vapor jetted from the mixing chamber, means for accelerating cluster ions produced in the ionization chamber and making them impinge on a substrate, and a substrate holder for holding the substrate.