First you have to have your toaster oven. Then you have to have the food that you want to heat up. You should press on or power to turn it on, then you should put what temperature you want it to be. Once you did that you can either put a timer on the oven for when it should stop, or you can just wait and then stop it. When you are ready to take the food out either press power or off to turn it off. It will probably be very hot so you should be careful. Then you are done.