A blowing apparatus for expanding containers with a gaseous medium has a blowing piston and a blowing nozzle, through which the container is expanded with the gaseous medium. The blowing piston is movable in a longitudinal direction (L) of the blowing nozzle, the blowing nozzle is movable in the longitudinal direction (L) relative to the blowing piston, and a guide device is provided which guides the movement of the blowing nozzle in the longitudinal direction (L) relative to the blowing piston.