This is a kind of metal scraper, used to move or remove embers and ash from the oven, especially just before closed fire cooking.
It's also useful for tending the fire, rearranging the woo, the embers....
Apparently in days gone by such rakes were often made of wood so as not to damage the fragile sole of the oven. For today's more robust ovens, metal rakes are more practical, given the high temperatures to which they are exposed.
If you intend to buy:
If you want to make one like this, you can start with a garden tool (a sort of wide hoe), then fix it onto a long metal handle.