There are some satin comforters you can wash in the washing machine. There are also duvets that need to be washed by hand. Some of the satin comforters can only be dry-cleaned.
You should always read the label before you wash your comforter. Otherwise, this will affect the fabric and it will not last as long as you would like it to. If you do not like to clean by hand or dry-clean you can always consider using a duvet cover. You will have to wash your satin comforter not that much.