Yes, according to the Bible NKJV. They are of the unseen realm...
2 Corinthians 4:18
while we do not look at the things which are seen, but at the things which are not seen. For the things which are seen are temporary, but the things which are not seen are eternal.
Demons will end up in hell, same as all those who do not belong to Jesus Christ...
“Then He will also say to those on the left hand, ‘Depart from Me, you cursed, into the everlasting fire prepared for the devil and his angels:
John 3:18 (NKJV)
18 “He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God.
By faith there is always hope in Jesus Christ for those who will repent of their evil ways
and believe in Jesus Christ, John 3:16-18, receiving the forgiveness of sins and eternal life.