CELL-CAPTURING DEVICE

A cell-capturing device includes: one or more introduction channels for introducing test liquid containing cells or treatment liquid for treating the cells in the test liquid into the inside thereof; a discharge channel for discharging the test liquid or the treatment liquid to the outside; a filter having a plurality of through-holes formed in a thickness direction, and being disposed in a channel between introduction channel and the discharge channel so that the test liquid or the treatment liquid passes through the through-holes; an introduction region formed between the filter and the introduction channel in a channel between the introduction channel and the discharge channel; a discharge region formed between the filter and the discharge channel; and a housing part accommodating at least a part of the introduction channel, the introduction region, and the discharge region therein, wherein the cell-capturing device further includes a pre-treatment part formed at a position apart from a connection part with the introduction region on at least one of the introduction channels, and formed by a spatial region having a diameter larger than that of the introduction channel.