Provided are an aggregate-removing filter material, an aggregate removal method, a white blood cell-removing filter, and a blood product filtering method, the filter material enabling the efficient removal of aggregates while preventing clogging by the aggregates. The aggregate-removing filter material for removing aggregates in blood products is composed only of fibers having a length of 100-1000mm and a density of 0.7-4.0dtex, has a basis weight of 20-100g/m