To provide a technique capable of automating killing of fish while keeping heart function, and automating a removal work of the larger amount of blood compared to heretofore even in the large fishes such as yellowtail, great amberjack, amberjack or tuna.

There is provided a method of removing the blood of fishes while keeping alive their heart functions. The method includes the steps of: posturing the fish so as to place its head lower than its tail; cutting the arterial vessels of medullary and the vicinity thereof by a cutting blade penetrated through branchia from the side of a fish body; opening a fish mouth and fixing; composing a closed space by covering the fish head including a cut place with a tubular fish body housing; and sucking/collecting the blood by generating a negative pressure in the closed space. The apparatus for carrying out the method is also provided.