Abstract: Activated treated water that can be manufactured by an extremely simple method and with which activation treatment can be performed on water that has not undergone activation treatment without direct contact. Activated treated water that is clustered water that has undergone activation treatment and thereby formed small molecule groups, wherein the ratio FID/FID0 of the free induction decay (FID) (units being seconds) of a peak originating in the hydrogen atoms in the water molecules in the hydrogen nuclear magnetic resonance spectrum for the activated treated water and the free induction decay FID0 (units being seconds) of a peak originating in the hydrogen atoms in the water molecules in the hydrogen nuclear magnetic resonance spectrum for water that has not undergone activation treatment is 0.80 or less.