A condensate filtering device of the present invention comprises a simulation unit which is able to simulate operating conditions being the same as operating conditions of a main body of an actual condensate filtering device and sample a hollow fiber membrane easily. The condensate filtering device comprises a unit evaluating properties of a hollow fiber membrane provided with a main body of the condensate filtering device containing a first hollow fiber membrane module in which filtration of condensate and air scrubbing washing are repeated, and equipped with a column containing a second hollow fiber membrane module having a hollow fiber membrane which is the same kind as the hollow fiber membrane of the first hollow fiber membrane module; and a line introducing the condensate for unit which is a branched line from a line introducing the condensate directing to the main body of the condensate filtering device and introduces the condensate into the unit evaluating the properties of the hollow fiber membrane.