PROBLEM TO BE SOLVED: To provide an algae-raising apparatus and an algae-raising method which can improve growth efficiency of algae.SOLUTION: An algae-raising apparatus 1 comprises: an algae tank 2 capable of housing a raising water 17 and Spirulina an LED3 which is arranged at an approximate center inside an algae tank body 2A and a gas dissolving machine 4 which is capable of dissolving at least one of carbon dioxide and oxygen into the raising water 17 inside the dissolving machine, and supplying carbon dioxide-dissolved water, oxygen-dissolved water and mixed dissolved water to the algae tank 2. Light is emitted inside the algae tank 2 in which the raising water 17 and Spirulina are housed by using the LED3. The raising water 17 is allowed to flow from the algae tank 2 into the dissolving machine body 4A filled with at least one of carbon dioxide and oxygen, and at least one of carbon dioxide and oxygen is dissolved into the raising water 17. Then, carbon dioxide-dissolved water, oxygen-dissolved water or mixed dissolved water, which is obtained, is supplied to the algae tank 2. The power generation part 7 generates power by using methane.SELECTED DRAWING: Figure 1
