Abstract: Due to the exotic electromagnetic properties, metamaterial absorber has spawned extensive research into wave absorption materials over the past decade. This paper provides an introduction on metamaterial absorber by summarizing the reports in recent years. The metamaterial absorber has progressed significantly with special function from narrow bandwidth to broad bandwidth, wide angle tolerance, polarization independence and smart/tunable absorbance. Meanwhile the working frequency across the electromagnetic spectrum is broadened from microwave to terahertz, near-infrared and optical. This paper introduces different types of metamaterial absorber and summarizes the fabrication, design method and working principle of metamaterial absorber. Finally, the promising research field of metamaterial absorber is predicted.