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

Provided is a bulk GaN crystal in which the degree of curvature of the c-plane is reduced. The bulk GaN crystal includes a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, and the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.05° or less.