If God is willing to give man a chance to repent and be saved, does he give Satan and his demons the same chance? Is it possible that Satan might repent and thus be saved?
Before we tackle that question, let's look at some characteristics of angels and demons first.
We know that God created everything and everything he created is good. (See Gen 1:31 and James 1:17.) In Psalm 148:1-6, the psalmist expresses praise to God for all his creation and among the things he created were the "angels" and "hosts". Furthermore, in Col 1:16, we read that through Christ all things on heaven and earth, visible and invisible, were created. This gives us further confidence that all creation, including angels, were created good.
So Satan, when he was first created by God, was good. How can he therefore become evil? Well, creation's goodness is finite, mutable (i.e., changeable) and corruptible. God's goodness on the other hand is infinite, immutable and incorruptible. In other words, while God will never turn to evil, the same is not true of his created beings. Secondly, evil is not something that is created, but it is a misuse or misdirection of good. When you choose to move away from God's goodness, that essentially is evil.
Okay, so in relation to Satan, he chose to rebel against God. Yes, he was created good, but no matter how glorious he might have been, he had his limitations. He saw things that he did not possess and he wanted them. He saw God's glory and he coveted it. In wanting what was not his, he could bring about evil by misusing the good that was in him. He chose to do this. He rebelled. He sinned.
We now have a better understanding of how God's creature could turn evil. Man also rebelled and fell into sin. But God provided a plan of redemption for man. God provided an atoning sacrifice in Jesus Christ and through Jesus, he redeemed the human race and brought glory to himself for his love, grace and mercy.
However, Satan and his demons were not offered salvation. Hebrews 2:16 says, "For surely it is not angels that he [God] helps, but he helps the offspring of Abraham." (The context here is deliverance from spirtual slavery and death.) God is saying here he saves man but not fallen angels, i.e., Satan and his demons. Also, 2 Peter 2:4 says, "God did not spare angels when they sinned, but cast them into hell and committed them to chains of gloomy darkness to be kept until the judgment." (See also Jude 6.) It therefore seems pretty clear that God does not intend to save fallen angels.
Furthermore, the Bible doesn't give us any reason to believe that Satan or his demons will repent if they were given a chance. Satan is bent on causing God as much destruction as possible. 1 Peter 5:8 says, "your adversary the devil prowls around like a roaring lion, seeking someone to devour." The Bible also tells us that one of the way God judges us is based on how much we know of him. "Everyone to whom much was given, of him much will be required, and from him to whom they entrusted much, they will demand the more." (Luke 12:48). Imagine how much more the fallen angels, with their superior intellect and the past time they've spent in God's presence, know about God and therefore, how much worse their judgment will be at the last day.
The answer to the question is therefore, no, Satan and his demons will not be saved. God did not intend for it to happen and they are not interested in being saved anyway. In the end, the most amazing thing is that we humans will be the ones to judge Satan and his demons. 1 Corinthians 6:3 says, "Do you not know that we are to judge angels?" And after the judgment, God will take Satan and his demons and throw them into the place he prepared for them, the lake of fire. (Revelation 20:10).