There are provided a nitrogen-containing heterocyclic compound such as a substituted amino-pyridine-N-oxide compound represented by formula (1), which is useful as a synthetic intermediate for an agrochemical and the like; and a method for producing the nitrogen-containing heterocyclic compound. (In formula (1), R1 and R2 each represents a hydrogen atom or an unsubstituted or substituted alkyl group; R3 represents a hydrogen atom, an unsubstituted or substituted alkylcarbonyl group or the like; R4 represents an unsubstituted or substituted alkylcarbonyl group, an unsubstituted or substituted arylcarbonyl group or the like; A represents a hydroxyl group, a thiol group or the like; m represents any one of integers of 1 to 4; k represents any one of integers of 0 to 3; and k+m≦4.)