An infarction prevention device has a filter to be placed inside a blood vessel. The filter includes a connection portion having a base end to be connected to a placing member configured to place the filter inside the blood vessel, and a cylindrical body portion connected to a front end of the connection portion. At least one of the connection portion and the cylindrical body portion includes a capturing portion configured to capture a foreign substance included in blood inside the blood vessel such that the at least one of the connection portion and the body portion controls a flow of the foreign substance.
