Tetrafluoromethane ($CF_4$) has been used as etching and Chemical Vapor Deposition (CVD) gases for semiconductor manufacturing processes. These gases need to be removed efficiently because of their strong absorption of infrared radiation and long atmospheric lifetimes which cause the global warming effect. Also, the wastewater including the fluorine is caused by of the ground water pollution. Long-term consumption of water containing excessive fluoride can lead to fluorosis of the teeth and bones. The wastewater including the fluorine among the by-product which is generated by using the waterjet plasma after destroying $CF_4$ by HF is generated. The system which can remove the hydrogen fluoride among the wastewater by using the electrocoagulation using this wastewater the aluminum electrode was developed. The operating condition such as initial pH, electrocoagulation time, wastewater flow rate, current density were investigated experimentally using a electrocoagulation. Through the parametric studies, the highest hydrogen fluoride destruction of 85% was achieved at 3.5 initial pH, 10 min electrocoagulation time, 10 mL/min wastewater flow rate and $159A/m^2$ current density.