A blood component collection cassette that can trap a substance where blood components coagulate by using a simple and economical configuration, and a manufacturing method of the blood component collection cassette are provided.A blood component collection cassette (28) includes a cassette main body (40) where a flow path (42) is formed and is configured to be mountable to a centrifugal separation device (14). The cassette main body (40) has a first sheet (40a) and a second sheet (40b) which are formed of a soft material. The flow path (42) is formed between the first sheet (40a) and the second sheet (40b). A filter member (60) for trapping a substance where blood components coagulate is arranged on the flow path (42) in the cassette main body (40).