You must make a request to Facebook for permanent deletion
If you don't think you'll use Facebook again, you can request to have your account permanently deleted. Please keep in mind that you won't be able to reactivate your account or retrieve anything you've added. Before you do this, you may want to download a copy of your info from Facebook. Then, if you'd like your account permanently deleted with no option for recovery, log into your account and let us know.
When you delete your account, people won't be able to see it on Facebook. It may take up to 90 days from the beginning of the deletion process to delete all of the things you've posted, like your photos, status updates or other data stored in backup systems. While we are deleting this information, it is inaccessible to other people using Facebook.
Some of the things you do on Facebook aren’t stored in your account. For example, a friend may still have messages from you even after you delete your account. That information remains after you delete your account.
https://www.facebook.com/help/224562897555674?helpref=faq_contentHow to Deactivate Facebook Account on Mobile
Deactivate from computer:
To deactivate your account:
- Click at the top right of any Facebook page.
- Select Settings.
- Click General in the left column.
- Choose Manage your account and then scroll down to click Deactivate your account.