GROUP III NITRIDE CRYSTAL MASS

PROBLEM TO BE SOLVED: To provide a group III nitride crystal mass having a large portion of a specific semi-polar plane on side faces other than a principal plane of a crystal surface.SOLUTION: A group III nitride crystal mass consisting of a group III nitride comprises a ground substrate that is a tabular seed crystal of a group III nitride having principal planes on front and rear surfaces and a group III nitride single crystal formed on the ground substrate, has at least one of a {10-11} plane and a {10-1-1} plane on a crystal surface, and satisfies a formula (A) (The principal planes of the front surface and the rear surface of the ground substrate may be nonparallel and their areas may be different). The formula (A) 0.45≤S2/S1 (In the formula (A), S1 represents the total area of the side face of the crystal surface nonparallel to the principal plate of the ground substrate and S2 represents the total area of the {10-11} plane and the {10-1-1} plane of the side faces of the crystal surface.).