Can I protect my directory from delete?

indeed,I want to prevent someone to delete the special directory,But I can’t set the directory readonly,for I need writing the data into it sometimes,How can I do?

The person should be able to write in there but not be able to delete the directory?

One option is to set the owner to root and put the sticky-bit (chmod u+t ), this will make the directory writable for all people, but just the fileowner or directory owner are allowed to delete change files in the directory or the directory itself. But take care to NOT create your special directory in the users homedirectory, or he can delete the dir any ways.

Another option is to set up the parent directory with no rights for the users →
ParentDir 755 root:root
|-- specialDir 777 root:root
|-- whateveryoulike…

the specialDir cannot be removed, but in the dir users can create total chaos ^^