Knee-protecting airbag and occupant's-leg-protecting apparatus

In order to provide a knee-protecting airbag (18) whose thickness when inflated is uniform in the lateral direction and which is capable of being inflated rapidly, and an occupant's-leg-protecting apparatus (14) including the knee-protecting airbag (18), in a knee-protecting airbag (18), a plurality of tethers (30) (30J and 30K) connecting a front side (18a) and a rear side (18b) are provided. Each tether (30) extends continuously in the lateral direction. The left edge (30L) and the right edge (30R) of each tether (30) are curved inward. Air-flow spaces (V) are formed between the left edge of each tether (30) and the left side of the airbag (18) and between the right edge (30R) of each tether (30) and the right side of the airbag (18).