<p>A fluid purifying apparatus that purifies fluid containing organic matter has a reactor including a first transfer part that receives the fluid from outside and transfers the fluid in a vertical direction from an upper side to a lower side while heating and pressurizing the fluid and mixing the fluid with an oxidant, a second transfer part that receives the fluid that has passed through the first transfer part and transfers the fluid in the vertical direction from the lower side to the upper side, and a partition member that partitions an upper part of the reactor into the first transfer part and the second transfer part, and a solid storage part that communicates with the first transfer part and the second transfer part below the partition member and receives solid matter contained in the fluid that settles while the fluid is transferred.</p>