A method for producing a nitrogen-containing organoxysilane compound having a general formula described below: wherein R 1 and R 2 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, the monovalent hydrocarbon group may include an oxygen, nitrogen, sulfur, or silicon atom in some cases, R 1 and R 2 may be bonded to each other to form a ring together with a nitrogen atom in some cases, and a case where both R 1 and R 2 are a hydrogen atom is excluded, R 3 represents an unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms, R 4 and R 5 represent an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and m is an integer of 0, 1, or 2, by reacting an amine compound having a general formula described below: wherein R 1 and R 2 are as described above, with a haloalkyl organoxysilane compound having a general formula described below: wherein R 3 to R 5 and m are as described above, and X represents a halogen atom selected from the group consisting of a chlorine atom, a bromine atom, and an iodine atom, the method comprising the steps of: using 0.1 mol or more and less than 1 mol of a nitrogen-containing compound having a general formula described below per 1 mol of the halogen atom in the haloalkyl organoxysilane compound having a general formula: wherein R 6 represents an unsubstituted divalent hydrocarbon group having 2 to 5 carbon atoms, and A represents a single bond, -NH-, or -NCH 3 -, and liquefying, in presence of a solvent, a mixture of the hydrogen halide salt of the amine compound having the general formula and the hydrogen halide salt of the nitrogen-containing compound having the general formula that are generated in the reaction system to separate the liquefied mixture from the nitrogen-containing organoxysilane compound having a general formula with liquid separation and removing the mixture, wherein the solvent is a protic polar solvent, wherein the protic polar solvent is an alcohol compound. by reacting an amine compound having a general formula described below: wherein R 1 and R 2 are as described above, with a haloalkyl organoxysilane compound having a general formula described below: wherein R 3 to R 5 and m are as described above, and X represents a halogen atom selected from the group consisting of a chlorine atom, a bromine atom, and an iodine atom, the method comprising the steps of: using 0.1 mol or more and less than 1 mol of a nitrogen-containing compound having a general formula described below per 1 mol of the halogen atom in the haloalkyl organoxysilane compound having a general formula: wherein R 6 represents an unsubstituted divalent hydrocarbon group having 2 to 5 carbon atoms, and A represents a single bond, -NH-, or -NCH 3 -, and liquefying, in presence of a solvent, a mixture of the hydrogen halide salt of the amine compound having the general formula and the hydrogen halide salt of the nitrogen-containing compound having the general formula that are generated in the reaction system to separate the liquefied mixture from the nitrogen-containing organoxysilane compound having a general formula with liquid separation and removing the mixture, wherein the solvent is a protic polar solvent, wherein the protic polar solvent is an alcohol compound. using 0.1 mol or more and less than 1 mol of a nitrogen-containing compound having a general formula described below per 1 mol of the halogen atom in the haloalkyl organoxysilane compound having a general formula: wherein R 6 represents an unsubstituted divalent hydrocarbon group having 2 to 5 carbon atoms, and A represents a single bond, -NH-, or -NCH 3 -, and liquefying, in presence of a solvent, a mixture of the hydrogen halide salt of the amine compound having the general formula and the hydrogen halide salt of the nitrogen-containing compound having the general formula that are generated in the reaction system to separate the liquefied mixture from the nitrogen-containing organoxysilane compound having a general formula with liquid separation and removing the mixture, wherein the solvent is a protic polar solvent, wherein the protic polar solvent is an alcohol compound.