Disclosed is a device for gas replacement capable of reducing the amount of replacement gas, improving a gas replacement rate, and reducing the amount of split liquid. In a replacement nozzle (11) which blows the replacement gas toward a container opening portion symmetrically about a center line in the container radial direction, the space between nozzle port outermost walls is divided with a plurality of wind direction adjustment plates (16a, 16b) to generate a plurality of blowout ports. The replacement gas flow blowing along the outermost walls of the nozzle opening are so blown inward as to form an angle of 100° to 130°. Moreover, the replacement gas is blown from the replacement nozzle to the range between the level lower than the end of the can opening by one third or more the height of the can neck portion and the level equal to or higher than the height of the can cover.