The present invention provides a golf ball comprising a spherical core composed of a spherical inner core layer and an outer core layer, an intermediate layer and a cover, wherein the inner core layer has a hardness difference (Hs1−Ho) between a surface hardness (Hs1) and a center hardness (Ho) of 5 or less in JIS-C hardness, the outer core is such that R2 of a linearly approximated curve obtained from a least square method is 0.95 or higher, when JIS-C hardness, measured at nine points obtained by dividing a thickness of the outer core in a radius direction of the spherical core into equal parts having 12.5% intervals therebetween, is plotted against distance (%) from a border point between the outer core layer and the inner core layer, and the intermediate layer has a slab hardness which is greater than a slab hardness of the cover.