To reduce costs associated with jellyfish disposal, by removing foreign matter, which is contained in seawater taken in by a deep water intake system, by means of a dust collector and returning jellyfishes, which are contained in the foreign matter, alive into the sea.

A jellyfish discharge system 1 includes: a curtain wall 10 which forms an intake area A by surrounding a water area on the periphery of an intake facility; a dust collector 14 which removes foreign matter from seawater taken in by an intake 5a of an intake facility 5; and a discharge passage 16 for carrying jellyfishes, which are contained in the foreign matter, into the sea. A net 12 for dividing the intake area A into first and second areas A1 and A2 and regulating the movement of the jellyfishes between the areas is installed in the curtain wall 10. The intake 5a is positioned in the first area A1. A wall surface part 10a of the curtain wall 10 has a height up to a tide level at full tide. The discharge passage 16 makes the jellyfishes discharged into the second area A2. The jellyfishes from the discharge passage 16 are stored in the second area A2. The jellyfishes in the second area A2 are discharged to the outside of the intake area A by the ebb tide after the full tide.