Abstract: The object of the present invention is to provide an organic-inorganic hybrid material having heat resistance, and said object of the present invention can be attained by providing an organic-inorganic hybrid prepolymer containing a phenyl group which is prepared by the polycondensation reaction accompanying dehydration between a polydimethylsiloxane and a metal and/or semimetal alkoxide, wherein (a) phenyl group(s) is (are) partially or wholly introduced into said polydimethylsiloxane and/or said metal and/or semimetal alkoxide.