A knee airbag module of a vehicle occupant restraint system comprises an outer housing (12) having a front side (14) including a deployment aperture (18) as well as an opposite rear side (16), an airbag (20) and an inflator (32) which provides filling gas for the deployment of the airbag (20). The airbag (20) is folded and in the folded state is retained by a flexible airbag wrapping (34) while forming an airbag package (24), wherein the airbag package (24) constitutes a pre-assembled unit and the flexible airbag wrapping (34) closes off the knee airbag module (10) at least in portions to the outside. There is provided a rigid outer housing part (42) which includes a first bearing zone (54) positioned in the area of the airbag package (24) against which the airbag (20) bears during deployment.