An elastomer composition is provided which contains a matrix of poly-(3-hydroxybutyrate-co-3-hydroxyhexanoate) produced from microorganisms and crosslinked natural rubber particles dispersed like islands in the matrix. An eraser using the elastomer composition is also provided. The present invention is capable of providing an elastomer composition and eraser using the same, which can be recycled, are friendly to the environment, and corresponds to the recycling society, without relying on fossil resources.