The demand for Apple's next iPhone is at an "unprecedented level," according to a new survey from ChangeWave.

The market research firm surveyed more than 4,000 consumers in mid-June and found that 14% said they were very likely to buy the next iPhone and 17% said they were somewhat likely to buy it. In other words, nearly a third of consumers say they will likely buy the fifth generation iPhone.

demand for iphoneChangeWave

ChangeWave notes that the demand for the next generation iPhone is "strikingly higher than we've seen for any previous iPhone model." Indeed, a similar survey conducted by the firm last year found that 21.5% of consumers were very likely or somewhat likely to buy the iPhone 4s, well below the demand this year.

demand for iPhoneChangeWave

A separate survey from Piper Jaffray analyst Gene Munster also found there is enough demand for the next iPhone to make it Apple's best selling phone yet.