An alkyl ether derivative represented by the general formula: wherein each of R1 and R2 represents one or more groups selected from a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkenyl group, an alkenyloxy group, an amino group, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, a heterocyclic group, a hydroxyl group, a carboxyl group, a nitro group, an oxo group and the like; R3 is an alkylamino group, an amino group, a hydroxyl group or the like; the ring A is a 5-membered or 6-membered heteroaromatic ring or a benzene ring; each of m and n is an integer of 1 to 6; and p is an integer of 1 to 3, or its salt has activity to protect neurons, activity to accelerate nerve regeneration and activity to accelerate neurite extension and hence is useful as a therapeutic agent for diseases in central and peripheral nerves.