PURPOSE: A novel composition useful as an insulating film, etc., capable of being cured in a short time without using a photosensitizer to provide an odorless cured material having improved heat resistance, comprising an Si compound having an o-nitrobenzyloxy group directly linked to Si.

CONSTITUTION: A photosetting silicon compound composition comprising an Si compound [e.g., trimethyl (o-nitrobenzyloxy)silane, etc.] having an o-nitrobenzyloxy group shown by the formula [R1WR4 are H, halogen, NO2, CN, 1W5C (substituted)alkyl, 1W5C alkoxy, (substituted) aryl, aryloxy, 1W5C acyloxy, OH, mercapto, acetyl, or aryl] directly linked to Si or the Si compound and a silanol condensation catalyst (e.g., dibutyltin dilaurate, lead octenoate, etc.).