To obtain a flexible flame-resistant nonwoven fiber structure resistant to ignition and having high mechanical properties resistant to the embrittlement by light and heat.

This flame-resistant nonwoven fiber structure has a coating layer composed essentially of particulate inorganic mineral selected from vermiculite and sepiolite or their mixture on at least one of the surfaces. The layer of the nonwoven structure contains at least one integrally bonded woven or knit fabric structure layer of a heat-resistant fiber in the cross-section of the layer.