We present a perfect metamaterial abosorber composed of metallic leaf-shaped cells, dielectric substrate and metallic film. Based on the metallic Drude principle, this structure can realize an perfect absorptivity of 99.5% at the infrared communication frequencies with appropriate geometric parameters. Moreover, this structure can simultaneously achieve perfect absorptions at two infrared frequencies with the maximal magnitudes of 99.67% and 97.13% respectively, which effectively broadens the bandwidth of absorptivity, thereby benefiting the design and the application of absorber at the infrared frequencies. Afterward, the effects of the neck width on the position of the double absorptivity peak are investigated, and expected to be used in frequency modulation. The model proposed in this paper has a series of advantages such as simple structure, high absorptivity and broad operating bandwidth.