Mauviel's M'Steel line is made of iron and carbon. This all natural material is similar to cast iron and needs to be seasoned to prevent rusting. Excellent pan for searing and general cooking, but not suggested for stewing or cooking with acidic foods due to potential loss of seasoning and reactivity of iron. After manufacturing these pans are coated in beeswax to protect them from rusting before purchase. Prior to first use, follow Mauviel's instructions for removing beesewax and then to season with high smokepoint, clear, flavorless oil. Performs well on all cooktops, including Induction, Gas and Electric. Not Dishwasher safe. Made in France.