The present invention provides an industrially advantageous method for producing a 1,4-benzoxazine compound useful as a medicine while avoiding safety and health risks. Specifically, the present invention provides a method for producing a 1,4-benzoxazine compound [A], which comprises the three steps in the following scheme, namely, a step of converting the amino group at 7-position in a compound [a] into a dimesylamino group, a step of coupling a compound [b] with a boronic acid compound, and a step of converting the 7-position in a compound [c] into a monomesylamino group. In the above scheme, Ms is a methanesulfonyl group, and each of R′ and R″ is a hydrogen atom etc.