An alkoxide compound of formula (I) suitable as a material for thin film formation used in thin film formation involving vaporization of a material such as CVD, a material for thin film formation including the alkoxide compound, and a process for thin film formation using the material. The process includes vaporizing the material for thin film formation, introducing the resulting vapor containing the alkoxide compound, onto a substrate, and causing the vapor to decompose and/or chemically react to form a thin film on the substrate. ##STR00001## wherein one of R.sup.1 and R.sup.2 represents an alkyl group having 1-4 carbon atoms, the other representing a hydrogen atom or an alkyl group having 1-4 carbon atoms; R.sup.3 and R.sup.4 each represent an alkyl group having 1-4 carbon atoms; A represents an alkanediyl group having 1-8 carbon atoms; M represents a silicon atom or a hafnium atom; and n represents 4.