Thich Thanh Cuong, head of a Buddhist monastery in Hai Duong province, was shown eating in restaurants, wearing civilian clothes and posing with the mobile phone, Bangkok Post reported.
The video clip and photos went viral on the internet, attracting widespread criticism.
The photos have been deleted since.
His actions "violated Buddhist morality and defamed the reputation of The Buddhist Sangha of Hai Duong province and he should receive serious punishment," Thich Quang Tung, head of the provincial Buddhist Sangha said.
Cuong said the iPhone 6 belonged to a follower who had imported the mobile phones into the country, and had given him one for good luck.
He said he returned the phone after being criticised for the photos.
Tung said the Buddhist Sangha would take measures to deal with the case depending on how repentant Cuong was.