Can I use it for deep diving about 40m?
No, not even snorkeling. Splashed water protection only.
For recreation diving (30m) I would use something like an i-Pix iPhone underwater Housing for iPhone 4\4S
Really deep stuff like 40m or more - look into professional cameras.
This is submergible to 6.6â?? (2m) for up to 60 minutes. It is not suitable for scuba diving.