The invention relates to a lighting balloon comprising a deformable envelope (12), at least one lighting means (18) mounted inside the envelope, and a supporting and stretching means for the envelope, provided with a plate (14) carrying the lighting means and with a longitudinally extending distancing element (16) mounted on the plate. The supporting and stretching means co-operates with an apex and a base of the envelope in order to stretch the envelope in the longitudinal direction. The balloon comprises at least one shape-maintaining means (30) mounted on the envelope and arranged transversely in relation to the distancing element.
