To provide a langasite (La3Ga5SiO14) type crystal in which any coloration, inclusion and crack are not caused and also to provide a production of a single crystal.

The production of the langasite type crystal using a Czochralski method comprises: using a powdery mixture obtained by mixing powdery lanthanum oxide, tantalum oxide and gallium oxide together in the stoichiometric composition ratio of lanthanum-tantalum-gallium oxide, as a material for a melt 6; and performing the crystal pulling-up in an atmosphere contg. argon and oxygen, wherein the concn. ratio of oxygen to argon is adjusted to 0.1 to 1.5 vol.%.