A drinking water filter system comprising: a filter unit comprising: a first electrode; and a second electrode disposed separate from and substantially opposite to the first electrode, wherein at least one of the first electrode and the second electrode are filter layers of activated carbon filters for filtering drinking water; and a voltage applying device which alternately and repeatedly applies a forward voltage and a reverse voltage between the first electrode and the second electrode to sterilize and regenerate the at least one filter layer. characterised in that the voltage applying device is configured to apply a voltage capable of electrolyzing water between the first electrode and the second electrode and to generate a positive electric potential of at least 1.4 V on the surface of at least one of the first electrode and the second electrode in a sterilization process of the filter layer; and the voltage applying device is configured to alternately apply a positive voltage and negative voltage to the first electrode and the second electrode in the regeneration process wherein the positive voltage is greater than 2V and equal to or less than 50V; and the drinking water filter system is configured to regenerate the filter layers by using the voltage applying device using tap water and without adding electrolyte in the filter unit. a filter unit comprising: a first electrode; and a second electrode disposed separate from and substantially opposite to the first electrode, wherein at least one of the first electrode and the second electrode are filter layers of activated carbon filters for filtering drinking water; and a voltage applying device which alternately and repeatedly applies a forward voltage and a reverse voltage between the first electrode and the second electrode to sterilize and regenerate the at least one filter layer. characterised in that the voltage applying device is configured to apply a voltage capable of electrolyzing water between the first electrode and the second electrode and to generate a positive electric potential of at least 1.4 V on the surface of at least one of the first electrode and the second electrode in a sterilization process of the filter layer; and the voltage applying device is configured to alternately apply a positive voltage and negative voltage to the first electrode and the second electrode in the regeneration process wherein the positive voltage is greater than 2V and equal to or less than 50V; and the drinking water filter system is configured to regenerate the filter layers by using the voltage applying device using tap water and without adding electrolyte in the filter unit. a first electrode; and a second electrode disposed separate from and substantially opposite to the first electrode, wherein at least one of the first electrode and the second electrode are filter layers of activated carbon filters for filtering drinking water; and a voltage applying device which alternately and repeatedly applies a forward voltage and a reverse voltage between the first electrode and the second electrode to sterilize and regenerate the at least one filter layer. characterised in that the voltage applying device is configured to apply a voltage capable of electrolyzing water between the first electrode and the second electrode and to generate a positive electric potential of at least 1.4 V on the surface of at least one of the first electrode and the second electrode in a sterilization process of the filter layer; and the voltage applying device is configured to alternately apply a positive voltage and negative voltage to the first electrode and the second electrode in the regeneration process wherein the positive voltage is greater than 2V and equal to or less than 50V; and the drinking water filter system is configured to regenerate the filter layers by using the voltage applying device using tap water and without adding electrolyte in the filter unit.