Golf ball 2 has a center 8, a mid layer 10, a cover 6 and dimples 12. The
mid layer 10 includes a styrene block-containing thermoplastic elastomer
having a material hardness of less than 10, and an ethylene-(meth)acrylic
acid copolymer-based ionomer resin having a material hardness of 50 or
greater and 70 or less. This mid layer 10 has a hardness equal to or less
than 50, and a thickness of equal to or less than 1.6 mm. The dimple has:
a first side wall face 18 that has a curvature radius R1 which is equal
to or greater than a phantom curvature radius Rx; a second side wall face
20 that is positioned to the bottom side than the first side wall 18 face
and has a curvature radius R2 which is smaller than the phantom curvature
radius Rx; and a bottom face 22 that is positioned to the bottom side
than the second side wall face 20 and has a curvature radius R3 which is
equal to or greater than the phantom curvature radius Rx.