A polyether compound having ether groups and vinyl double bonds represented by formula (I) ##STR1## wherein R.sub.1 represents a residue of an organic compound having l active hydrogen atoms, n.sub.1 through n.sub.l each represents 0 or an integer of from 1 to 100, the sum of the integers represented by n.sub.1 through n.sub.l is from 1 to 100, andl represents an integer of from 1 to 100, and A represents ##STR2## and a process for production thereof; an epoxy resin represented by formula (II) ##STR3## wherein R.sub.1 and n.sub.1 through n.sub.l are defined above, and B is an oxycyclohexane unit having a substituent and is represented by formula (III) ##STR4## wherein X represents a ##STR5## --CH.dbd.CH.sub.2, or ##STR6## groups, wherein R.sub.2 represents an alkyl group, an alkylcarbonyl group, or an arylcarbonyl group, provided that the epoxy resin represented by formula (II) contains at least one ##STR7## group, and a process for production thereof; and an epoxy resin comprising an epoxy resin as in formula (II), are disclosed.