I don't want to use my iphone as a phone anymore

If i don't want to use it as a phone… Can I use it as an ipod?

Yes you can…

Yes, you can. If you remove the cellular service from it, it will still work just fine, however calling, SMS or MMS text messages, and cellular data will not work. You can still use iMessage or other messaging apps, and access the Internet via Wi-Fi.