PURPOSE: To obtain new low-viscosity, linear and highly reactive glycidyl ethers, having a low viscosity and useful for producing a water- and chemical-resistant cured product excellent in flexibility by curing thereof with a curing agent.

CONSTITUTION: The low-viscosity and linear glycidyl ethers are expressed b) formula I [X is formula II, III or IV; R is H or CH3; (m) is 1-2; (n) is 5-50] and have ≤5 Pa.a viscosity (at 60°C), e.g. a compound expressed by formula V. The compounds expressed by formula I are obtained by carrying out the addition reaction of a glycidyl ether of a polyether polyol with polyfunctional phenols and then condensing the resultant compound having one or more phenolic hydroxyl groups in one molecule with an α-epihalohydrin in the presence of an alkali. A curable composition obtained from the compounds expressed by formula I is especially useful in the field of coatings, adhesives, coating agents and sealing agents.