Also Read: Make an invisible Folder to protect private files
First of all, make sure you are signed into your account you are about to delete and then open this link.
Now press the "Delete my account" button and enter your account password, complete security check, and press the OK button.
After success, you will get warning message like in the picture below.
After 14 days, your account will be removed from Facebook completely. But you can log into your account within 14 days if you want to cancel the account deletion request.