CaF2 single crystals suitable for excimer laser application in the ultraviolet range were grown by the Czochralski method. ZnF2 additive and CF4 gas were successfully used as scavengers for removing the water molecules in the growth environment, which otherwise cause various defects such as subgrain boundaries, bubbles and oxygen-related precipitates in the CaF2 crystal. Czochralski-grown CaF2 crystals had very good crystallinity and a high transmittance in the wavelength range of the ultraviolet laser. The defect structures of colored and colorless CaF2 crystals were compared.