Method for operating filtration apparatus and filtration apparatus

2:

• The method for operating a filtration apparatus according to claim 1, wherein, in the cleaning step, a plurality of filtration modules that have not been cleaned for the same or nearly the same amount of time as one another are cleaned simultaneously.

3:

• The method for operating a filtration apparatus according to claim 2, wherein a difference between the amounts of time during which the filtration modules have not been cleaned is 5% or less.

4:

• The method for operating a filtration apparatus according to claim 1, wherein the total number of the filtration modules included in the filtration apparatus is even, and half of all the filtration modules are cleaned simultaneously in the cleaning step.

5:

• The method for operating a filtration apparatus according to claim 1, wherein the amount of time during which cleaning is performed in the cleaning step is 0.3% or more and 5% or less of the amount of time during which the filtration treatment is performed.