A process, advantageous in producibility, for the production of a vinyl compound containing very small amounts of ionic impurities and hydrolysable halogens, which is capable of curing by means of heat and/or light and giving a cured product having excellent dielectric characteristics and heat resistance, which process can efficiently remove a generated salt and comprises reacting a non-protonic polar solvent solution of a specific bifunctional phenylene ether oligomer with a vinylbenzyl halide in the presence of an alkoxide of an alkali metal, wherein the thus-obtained reaction solution is acidified with a specific amount of an acidic substance, then a salt generated is removed, an alkali substance containing a specific amount of an alkali metal is added to the thus-obtained solution, then a salt generated is removed, and the thus-obtained solution is mixed with water or a water-alcohol mixed solution, to precipitate a solid.