How is the Earth's magnetic field made?

Answer 1

The earth's core is made out of nickel and iron. Most things made of this are at least a little bit magnetized. The core is also spinning a little faster than the rest of the earth, which causes the magnetic poles to drift over time.

Answer 2

One way to create a magnetic field is to have hot metal spinning around. And we do, the earth's core is molten iron/nickel spinning around inside the earth and that motion is what creates the magnetic field.