With a few exceptions, you can use most of today's cookware on a glass-top stove. The general rules are that your cookware should be heavy; have a flat, even bottom with no ridges; and be able to withstand the heat produced by the recessed coils. A cast-iron skillet meets all these requirements, and you can use it as long as you keep a few important points in mind.
The Cookware Manufacturers Association states that cast iron is safe to use on a glass-top stove as long as you understand its unique characteristics. Be sure the skillet fits the size of the element or extends just an inch or so beyond the outermost ring imprinted in the glass. Check the bottom of the skillet for small burrs, and file these off with a steel rasp before using. As with all cookware used on a glass-top stove, lift and move the skillet rather than sliding it to minimize the likelihood of scratching the glass.
Procedure and Safety
Place the skillet on the burner before turning it on, and set it to no higher than medium. Test the skillet with a drop or two of water and add cooking fats or foods when the water evaporates. Reduce the heat to low as the food cooks, and turn it off shortly before it is done, as cooking will continue from the residual heat. Cast-iron handles get very hot, so be sure to use a potholder or oven mitt when handling them. To minimize cleanup, put the empty skillet back on the burner, pour hot water into it and allow it to soak until you are ready to rinse it out.