What is my Paella Pan made of?
This kind of pan is traditionally made of blue steel. The coating on it would be a homemade seasoning from oil. 

I cannot tell it 100% from just the small picture, especially since there are manufacturers who sometimes imitate traditional looks while using different materials, but this is the likeliest guess for this pan. 

If it is indeed a seasoned blue steel pan, then the seasoning can take any temperature at which food is cookable. If you take it so far that it burns off (which would take something around 500-600 Celsius, so unlikely to happen in a home kitchen) you can replace it yourself, although you might need a few tries until you get it right.