Disclosed is a method for producing an .alpha.,.beta.-unsaturated ether efficiently and stably for a long time. In the method for producing an .alpha.,.beta.-unsaturated ether, an acetal is thermally decomposed in the presence of a catalyst containing an apatite represented by any of the following formula (1)-(4) (M).sub.5-y(HZO.sub.4).sub.y(ZO.sub.4).sub.3-y(X).sub.1-y (1) (M).sub.5-y(HPO.sub.4).sub.y(PO.sub.4).sub.3-y(X).sub.1-y (2) (M).sub.5-y+2n(HZO.sub.4).sub.y(ZO.sub.4).sub.3-y(X).sub.1-y(SiO.sub.4).s- ub.n (3) (M).sub.5-y+m(HZO.sub.4).sub.y(ZO.sub.4).sub.3-y(X).sub.1-y(CO.s- ub.3).sub.m (4).