A man can divorce his wife for pretty much anything.

If any man take a wife, and goin unto her, and hate her.... Deuteronomy 22:13

Like when he sees some uncleanness in her. (Or if she no longer has favor in his eyes.)

When a man hath taken a wife, and married her, and it come to pass that she find no favour in his eyes, because he hath found some uncleanness in her: then let him write her a bill of divorcement, and give it in her hand, and send her out of his house. And when she is departed out of his house, she may go and be another man's wife. Deuteronomy 24:1-2

But Jesus disagrees. He says that a man can't divorce his wife unless she has fornicated.

It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement: But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery. Matthew 5:31-32

Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery. Matthew 19:9

But Jesus disagrees with himself, saying that divorce is never permissible.

Whosoever shall put away his wife, and marry another, committeth adultery. Mark 10:11, Luke 16:18

And Paul says that it's okay to divorce an unbelieving spouse.

But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases. 1 Corinthians 7:15

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See also When is divorce permissible?