Multi-piece solid golf ball

A multi-piece solid golf ball comprising a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and a cover which encases the intermediate layer and has formed on a surface thereof a plurality of dimples, wherein the envelope layer consists of an inner envelope layer, an intermediate envelope layer and an outer envelope layer;

• the inner, intermediate and outer envelope layers, the intermediate layer and the cover are so each formed primarily of a resin material which may be of the same or different types;
• the core is formed primarily of a rubber material;
• the cover has a material hardness (Shore D) and the core has a center hardness (Shore D) which satisfy the following condition:
• cover material hardness≦core center hardness;
• and one of the inner layers has a material hardness (Shore D) which is higher than either or both of the cover material hardness (Shore D) and the average core hardness (defined as the arithmetic mean of the core surface hardness and the core center hardness),
• wherein the intermediate envelope layer is formed so as to be harder than the inner envelope layer and to have a material hardness difference (Shore D) with the inner envelope layer of from 1 to 6, and so as to be softer than the outer envelope layer and to have a material hardness difference (Shore D) with the outer envelope layer of from 1 to 6,
• and wherein the following relationship is satisfied:
• intermediate envelope layer material hardness>average core hardness>core center hardness.