To provide a knee protecting airbag system capable of conveniently handling a knee panel and easily adaptable to the change of a vehicle type to be equipped therewith.

The knee protecting airbag system has a sheet metal-made case 17 which is arranged on the forward side to store a folded airbag and an inflator 64 while a backward side of the vehicle is opened, and a sheet metal-made knee panel 43 which extends outwardly from an opening circumferential edge of the case 17 to support the developed and inflated airbag on the forward side of the vehicle. The knee panel 43 is separate from the case 17, and divided into a part 46 arranged on the left side of the case 17 and a part 44 arranged on the right side thereof, which are respectively connected to the case 17.