To provide a rubber composition having a higher fracture property as compared with a conventional rubber composition obtained by mixing reclaimed rubber, powdered rubber or the like, and capable of improving a material recycling rate of waste rubber.

The rubber composition comprises micro-crushed rubber produced by a method including (i) a coarse-crushing step for processing a crushed rubber raw material to a coarse-crushed rubber by a coarse-crushing means 7, (ii) a micro-crushing step for processing the coarse-crushed rubber to micro-crushed rubber by a fine-crushing means 8 provided with micro-crushing rolls 8a, 8b and (iii) a separation step for applying an impact force to rubber granules which are contained in the micro-crushed rubber and connected to each other, by a separator 3 to forcibly separate them and form micro-crushed rubber.