PROBLEM TO BE SOLVED: To provide an aquatic life raising method and an aquatic life raising device capable of improving growth efficiency of an aquatic life.SOLUTION: An eel raising device 1 comprises: a growth tank 2 capable of storing growth water and eels; a precipitation tank 3 for precipitating excrement of eels and residue of food of eels; and an oxygen dissolution machine 4 capable of dissolving oxygen into the growth water and supplying an oxygen dissolution liquid to the growth tank 2. Food for eels containing a mineral-containing substance containing mineral, aerobic microorganisms, and oxygen, is put into the growth tank 2 storing the growth water and the eels. The oxygen is supplied to a dissolution machine body 4A of the oxygen dissolution machine 4 communicated to the growth tank 2, then the growth water is made to flow from the growth tank 2 and the precipitation tank 3 to the dissolution machine body 4 filled with oxygen, while maintaining pressure of the growth water which is lower than oxyge
