A mold for a golf ball includes an upper portion (1) and a lower portion
(3). A large number of projections (7) for dimple formation are provided
on a cavity surface (5) of each of the upper portion (1) and the lower
portion (3). A parting surface (8) of the upper portion (1) and the lower
portion (3) has a concavo-convex shape. The parting surface (8) includes
a first horizontal plane (13), a second horizontal plane (15) and an
inclined surface (17). Circumferential central angles .phi. of the first
horizontal plane (13) and the second horizontal plane (15) are 55 degrees
or less. A total value .SIGMA..phi. of the circumferential central angles
.phi. is 30 degrees to 330 degrees. An inclination angle .alpha. of the
inclined surface (17) to a horizontal direction is 10 degrees to 60
degrees. A central angle .theta. between the horizontal planes (13) and
(15) and an equator (E) is 1 degree to 8 degrees. A boundary corner
portion of the horizontal planes (13) and (15) and the inclined surface
(17) is subjected to rounding.