A process for preparing an alkoxymethyl alkynyl ether compound having a terminal triple bond of the following formula: wherein R represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group, and "a" represents an integer of 1 to 10, the method comprising subjecting an alkynol compound having a terminal triple bond of the following formula: wherein a is as defined above, to an alkoxymethylation with a halomethyl alkyl ether compound of the following formula: RCH 2 OCH 2 X wherein X represents a halogen atom, and R is as defined above, in the presence of a dialkylaniline compound of the following formula: [CH 3 (CH 2) b][CH 3 (CH 2) c]NC 6 H 5 wherein b and c represent, independently of each other, an integer of 0 to 9, to form the alkoxymethyl alkynyl ether compound having a terminal triple bond, (i) wherein the alkoxymethylation is carried out without any additional solvent, or (ii) wherein a reaction mixture (organic phase) containing the alkoxymethyl alkynyl ether compound obtained in the alkoxymethylation and the hydrogen halide salt of the dialkylaniline compound is neutralized with a base in the presence of water to obtain an organic phase containing the alkoxymethyl alkynyl ether compound and dialkylaniline compound (neutralization step), or (iii) wherein the alkoxymethylation is carried out without any additional solvent, and a reaction mixture (organic phase) containing the alkoxymethyl alkynyl ether compound obtained in the alkoxymethylation and the hydrogen halide salt of the dialkylaniline compound is neutralized with a base in the presence of water to obtain an organic phase containing the alkoxymethyl alkynyl ether compound and dialkylaniline compound (neutralization step). wherein R represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group, and "a" represents an integer of 1 to 10, the method comprising subjecting an alkynol compound having a terminal triple bond of the following formula: wherein a is as defined above, to an alkoxymethylation with a halomethyl alkyl ether compound of the following formula: RCH 2 OCH 2 X wherein X represents a halogen atom, and R is as defined above, in the presence of a dialkylaniline compound of the following formula: [CH 3 (CH 2) b][CH 3 (CH 2) c]NC 6 H 5 wherein b and c represent, independently of each other, an integer of 0 to 9, to form the alkoxymethyl alkynyl ether compound having a terminal triple bond, (i) wherein the alkoxymethylation is carried out without any additional solvent, or (ii) wherein a reaction mixture (organic phase) containing the alkoxymethyl alkynyl ether compound obtained in the alkoxymethylation and the hydrogen halide salt of the dialkylaniline compound is neutralized with a base in the presence of water to obtain an organic phase containing the alkoxymethyl alkynyl ether compound and dialkylaniline compound (neutralization step), or (iii) wherein the alkoxymethylation is carried out without any additional solvent, and a reaction mixture (organic phase) containing the alkoxymethyl alkynyl ether compound obtained in the alkoxymethylation and the hydrogen halide salt of the dialkylaniline compound is neutralized with a base in the presence of water to obtain an organic phase containing the alkoxymethyl alkynyl ether compound and dialkylaniline compound (neutralization step). (i) wherein the alkoxymethylation is carried out without any additional solvent, or (ii) wherein a reaction mixture (organic phase) containing the alkoxymethyl alkynyl ether compound obtained in the alkoxymethylation and the hydrogen halide salt of the dialkylaniline compound is neutralized with a base in the presence of water to obtain an organic phase containing the alkoxymethyl alkynyl ether compound and dialkylaniline compound (neutralization step), or (iii) wherein the alkoxymethylation is carried out without any additional solvent, and a reaction mixture (organic phase) containing the alkoxymethyl alkynyl ether compound obtained in the alkoxymethylation and the hydrogen halide salt of the dialkylaniline compound is neutralized with a base in the presence of water to obtain an organic phase containing the alkoxymethyl alkynyl ether compound and dialkylaniline compound (neutralization step).