A hinge connection at a breathing gas supply unit between a container lower part (3) and a container door (4), which is fastened, pivotably around an axis, at a rear container edge (1) of the container lower part (3). The connection is provided such that dimensional differences of the container lower part can have only a limited effect on the positioning of the container door in relation to adjacent components of the breathing gas supply unit. The axis of the hinge is designed as projections (15) located at a spaced location from hinge pins (14) of a rail section (2) in the manner of a pin.