MR phase information has been used in many MRI applications, recently, so it is very important to estimate the correct MR phase. Since the MR phase is encoded in complex exponential, the actual phase information obtained is in the form of a wrapped signal. Unfortunately, conventional MR phase unwrap methods are highly related to SNR and require a lot of computation, so an efficient method is needed.. Here, we propose ViT-PU-Net to perform 3D phase unwrap using ViT-based encoder architecture. Therefore, we investigated whether this architecture could be applied to 3D phase unwrap task by applying it to various data.