CZT is one of the most promising materials for X-ray and γ-ray radiation detectors operated at room temperature. We have studied the fabrication process of the CZT planar-type detector, which includes the physical and chemical surface treatment, the fabrication of metal contact, and the surface passivation. CZT planar-type detectors with various metal-semiconductor contacts were made. The dark current and the γ-rays from 241Am were measured with each detector, and they were compared. From the above studies, the effective fabrication method of CZT detector could be deduced. Our work could be helpful to fabricate the high resolution CZT detector, which could be used in various application areas such as nuclear medicine, radiation safety, X-ray and γ-ray astronomy and homeland security