Provided are a cancer cell-trapping metal filter which has a high opening ratio, a cancer cell-trapping metal filter sheet, a cancer cell-trapping device using the cancer cell-trapping filter, and manufacturing methods therefor.According to a cancer cell-trapping metal filter 1, openings of connected through-holes 12 that are formed in a metal sheet 11 have a wave shape, and thus it is possible to extract a CTC from other components by utilizing a hole diameter on a short-side side of the openings, and it is possible to make the connected through-holes be closer to each other due to the wave shape while maintaining a CTC trapping ability. Accordingly, it is possible to further improve the opening ratio in the cancer cell-trapping metal filter 1.