Golf ball 2 has a spherical core 4, a reinforcing layer 6 positioned outside of the core 4 and a cover 8 positioned outside of the reinforcing layer 6. The core 4 has a inner sphere 10, a first mid layer 12 positioned outside of the inner sphere 10, and a second mid layer 14 positioned outside of the first mid layer 12. The principal component of the first mid layer 12 and the second mid layer 14 is an ionomer resin. The principal component of the cover 8 is a thermoplastic polyurethane elastomer. The second mid layer 14 has a hardness Hs which is greater than a hardness Hf of the first mid layer 12 and a hardness Hc of the cover 8. The hardness Hc of the cover 8 is equal to or less than 50. A product (TcHc) of a thickness Tc (mm) and a hardness Hc of the cover 8 is equal to or less than 25.