Among them, is a method utilizing a starting material available at relatively low cost, that is, a method of producing etheramine by reacting sodium N,N-dimethylaminoethoxide (hereinafter abbreviated to Na-DMAE) derived from N,N-dimethylethanolamine (hereinafter abbreviated to DMEA) with sulfuric anhydride (SO3) is disclosed in British Patent Publication No. 2,010,839 (Japanese Kokai Patent Applic