PROBLEM TO BE SOLVED: To automatize switching between filtration and concentration processing and re-concentration processing by integrating a filtration and concentration circuit with a re-concentration circuit.SOLUTION: An ascites processing device 1 includes: a filtration circuit 12 capable of supplying ascites in an ascites bag 10 to an ascites filter 11 a concentration circuit 15 capable of circulating the ascites through an ascites concentrator 13 and a concentrated ascites bag 14 a connection circuit 16 for connecting the filtration circuit 12 to the concentration circuit 15 a gas supply circuit 18 capable of supplying gas to a secondary side 11b of a filtration film 17 of the ascites filter 11 and a control part 19 for supplying the ascites in the ascites bag 10 to the ascites filter 11 for filtration, supplying the ascites to the ascites concentrator 13 through the connection circuit 16 for concentration, supplying the ascites to the concentrated ascites bag 14, subsequently supplying gas to the secondary side 11b of the ascites filter 11 through the gas supply circuit 18, supplying the ascites remaining in the secondary side 11b and the connection circuit 16 to the concentration circuit 15, and subsequently circulating the ascites of the concentration circuit 15 for re-concentration.
