Bulk GaN crystal, c-plane GaN wafer, and method for manufacturing bulk GaN crystal

In order to provide a bulk GaN crystal in which the degree of curvature of the c-plane is reduced, the present invention provides a bulk GaN crystal having a principal surface selected from a surface that is inclined 0 degrees to 10 degrees from the (0001) crystal plane and a surface that is inclined 0 degrees to 10 degrees from the (000-1) crystal plane, the principal surface being a specific principal surface A that satisfies conditions (i) and (ii) below. (i): A first line as a virtual line segment having a length of 80 mm that extends in a first direction on the specific principal surface A can be drawn, and the difference between the maximum value and the minimum value of the peak angle of (002) XRD rocking curves of the GaN crystal, measured between 17 measurement points arranged at a 5-mm pitch on the first line and with the [omega] axis perpendicular to the first direction, is 0.05 degrees or less. (ii): A second line as a virtual line segment having a length of 80 mm that extends in a second directio