PURPOSE: To produce a rare earth metal alcoholate transformable into the vaopor phase without being decomposed at a low temp. and having a solubility and volatility.

CONSTITUTION: The rare earth metal alcoholate in which ligands form a 5 or 6-membered ring including a metallic atom, adjacent oxygen atoms, two or three carbon atoms and an electron donating atom (nitrogen or oxygen) under the influence of the center rare earth metal atom, and in which the organic residue bonded with the carbon atoms is hydrogen atom, methyl group, ethyl-group, isopropyl group or tertiary buthyl group.