It is an object of the present invention to provide a dielectric elastomer composition which has a sufficient dielectric property as a high-frequency electronic component material and to which an excellent flame retardance can be imparted as necessary in consideration of an influence on environment and the high-frequency electronic component material formed by molding the dielectric elastomer composition. The dielectric elastomer composition of the present invention comprises an elastomer to which (A) carbon black and (B) at least one powder selected from among magnesium hydroxide powder and dielectric ceramic powder is added. An average particle diameter of the carbon black is 50 to 200 nm, and 5 to 40 parts by weight thereof is added to 100 parts by weight of the elastomer. In the magnesium hydroxide powder, a content of ferric oxide is not more than 0.02 wt %. In at least one measuring condition selected from among a measuring condition (1) in which a frequency is 400 MHz and a temperature is 30° C. and a measuring condition (2) in which a frequency is 5 GHz and a temperature is 25° C., a dielectric constant is not less than three, and a dielectric dissipation factor is not more than 0.01.