A method for producing a 3-(substituted oxy)-4-pyridazinol compound represented by the following general formula (I): comprising reacting a compound represented by the following general formula (III): with a compound represented by the following general formula (IV): MO—R2  (IV). The compound represented by the general formula (I) can be reacted with a compound represented by the following general formula (VI): to provide a compound of general formula (V): Each of the groups in the formulas is defined. The compounds of general formulas (I) and (V) can be obtained in a high yield and with high selectivity at a low cost, and therefore various functional and active substances can be advantageously synthesized using the compounds as a medicine, an agricultural chemical, a functional material, or an intermediate thereof.