A blood cells removal module including a casing having an inlet into which a blood flow before blood cells removal flows, and an outlet in which a blood flow after blood cells removal is discharged, an adsorbent for blood cells removal of short fiber shape accommodated in the casing, a mesh being provided inside the inlet and the outlet, respectively, and holding the adsorbent for blood cells removal in the casing, wherein a length of the adsorbent for blood cells removal is within a range from 1 to 60% of the internal diameter of the casing.