PURPOSE: To improve a defoaming rate by removing the foam intruding into the high-viscosity fluid to be packed into a constant quantity discharging container body.

CONSTITUTION: While the high-viscosity fluid 2 is pressurized and is packed from a nozzle 6a of the constant quantity discharging container body 5, the opening end of a cylinder 6 of the constant quantity discharging container body 5 is hermetically closed by a cap body 8. A spring member 9 is interposed between this cap body 8 and a piston member 7 moving back and forth in the cylinder 6 and an air suction means which intermittently sucks the air in the cylinder 6 is connected to the cap body 8.