A blood processing filter for removing undesirable components from liquid containing a blood component or blood, comprises: a sheet-shaped filter element and a container that includes an inlet-side container element and an outlet-side container element that are disposed to clamp the filter element, and has an internal space separated by the filter element into an inlet space and an outlet space, wherein the filter element includes a filtering surface on a side of the inlet space, a filtering surface on a side of the outlet space, and an end surface along peripheries of the pair of filtering surfaces, and the inlet-side container element and the outlet-side container element are provided with a gripper, and the gripper clamps and compresses an outer edge portion of the pair of filtering surfaces, and is caused to adhere to the end surface with melt resin.