PURPOSE: To obtain an inexpensive vapor-liquid contacting apparatus having good oxygen dissolution efficiency by arranging a plural number of straight pipe type ejectors whose walls are provided with small holes by piercing them through a gas supply pipe.

CONSTITUTION: The straight pipe type ejector 5 provided with a throat portion and diffuser portion integrally is fitted into the gas supply pipe 1 throughly. The pipe 5 is provided with a plural number of the vapor suction ports 13 and the nozzle 6 is inserted into the throat portion of the pipe 5. The nozzle-attached side of the pipe wall is made up of the cover 7 and the wall 1, where the pressurized water introduction space 8 is provided. Because the pipe body 5 and the nozzle 6 are pressed by the pressure of the pressrurized water, the structure of the vapor-liquid contacting apparatus can be simplified and also the use of a large number of ejectors is made easier.