A process for producing a monoalkyl ether which comprises a first step of contacting the following components (A) and (B):(A): an aqueous liquid phase containing: (a1) a C3-6 polyol having 3 or 4 hydroxyl groups, a palladium compound, a water-soluble tertiary phosphine or phosphite, and water; or (a2) a C3-6 polyol having 3 to 4 hydroxyl groups, a complex of palladium and a water-soluble tertiary phosphine or phosphite, and water, and (B): an oily liquid phase containing a conjugated diene, to give an alkadienyl ether containing an alkadienyl group resulting from dimerization of conjugated dienes; and a second step of hydrogenating the alkadienyl group in the alkadienyl ether in a hydrogen atmosphere in the presence of a catalyst containing an element selected from the Groups 8 to 10 elements of the periodic table. According to the process of the invention, monoalkyl ethers of polyols are produced selectively in a simple manner and advantageously from the economical viewpoint. The present process enables recovery and recycling of the catalyst.