The product description often states whether an oven is dishwasher-safe. In addition, every baking machine has instructions in the user manual on how best to clean it.
As a rule, you can clean an automatic oven by hand using washing-up liquid. It is important that you disconnect the appliance from the power supply before cleaning! It is best to clean your baking machine directly after you have used it, as this makes it easier to remove the dirt.
Before using it again, make sure that you have dried it thoroughly. Otherwise it may have a negative effect on your dough.