Electromagnetic waves emitted by electrical and electronic devices constitute interference with each other, which becomes a problem for security devices, space vehicles, ships, electronics or even human beings. Electromagnetic interference (EMI) protective materials are being developed to eliminate such negative effects of electromagnetic waves. Especially carbon-based ones are becoming increasingly important. The carbonized material biochar, derived from biomass, emerges as a sustainable, renewable, environmentally friendly and inexpensive EMI material. In this study EMI protective effect of biochar derived from industrial tea waste biomass and its iron composite was investigated. The effect values of the samples were found to be greater than 10 dB.