The present inventive concept provides a method of manufacturing graphene using electrochemistry, the method including dipping a cathode including metal and an anode including graphite into an electrolyte and applying a DC power supply between the cathode and the anode, wherein the DC power supply is a DC switching power supply applying a positive (+) voltage and a negative (−) voltage alternately and repetitively. The method according to the present inventive concept can simply mass-produce high purity graphene by applying the DC switching power supply, thereby efficiently controlling the ions to peel the graphite.