The original fireworks were made from gunpowder, which is a mixture of ingredients including saltpetre, sulphur and charcoal.
Today, experts at handling explosives, called pyrotechnicians, add chemicals for special effects.
There are many different types of fireworks, but they are all made in pretty much the same way.
Ingredients are placed in a shell, the whole thing is wrapped up and then a fuse is added.
In the factories where fireworks are made, safety precautions are used to make sure a single static electric shock doesn't create an explosion.