A cell trapping device 1 includes: a housing 10, a filter, and a plurality of fastening members 60. The housing 10 includes: a lid member 100 having an introduction channel 101 configured to introduce a test liquid into an inside; and a storage member 200 having a discharge channel 201 configured to discharge the test liquid to an outside. The filter is provided on a channel in the housing 10 and supported between the lid member 100 and the storage member 200 by the lid member 100 and the storage member 200. The fastening members 60 configured to clamp the lid member 100 and the storage member 200 from both sides in an intersecting direction that is a direction intersecting with the filter to fasten the lid member 100 and the storage member 200 to each other.