PURPOSE: To prevent damage of conveyed goods by utilizing both inflow of gas on a suction side and injection of pressurized liquid under definite conditions at an intermediate position.

CONSTITUTION: Living fish 4 in a fishing net 3 is sucked and conveyed in a pipe 7 by pressurized water from a pressurized liquid injecting portion 6 at an intermediate position together with air from a gas inflow portion 5. The apparent specific gravity of fish in a liquid can be reduced and buoyancy can be produced by flowing gas from the suction side, thereby to prevent a cavitation phenomenon which occurs frequently in case of an ejector suction method and prevent damage of fish.