To provide an electromagnetic wave absorber having essential performances therefor, the fire-resistance of V0 level for UL94 fire-resistance standard, excellent stability in dimension against temperature change, and no substantial shift in absorbance peak frequency when a temperature rises within a temperature range for normal use.

Related to the electromagnetic wave absorber wherein a chlorinated polyethylene rubber is matrix with which the powder of soft magnetic metal is mixed, one or two kinds of aluminum hydroxide and magnesium hydroxide are used as fire-resistant agent, with the mixture of fire-resistant agent occupying at least 25 vol.%, and the total amount of soft magnetic metal powder and fire-resistant agent is within a range of 50-75 vol.% of the mixture.