An endoscope system having: an endoscope having: an endoscope insertion section configured to be inserted into a subject, wherein the endoscope insertion section defines a channel having a distal opening and a power transmission electrode arranged to the endoscope insertion section and electrically connected to a power source configured to output a high-frequency power and a treatment tool having: an electrically powered treatment device a treatment tool insertion section attached to the electrically powered treatment device, wherein the treatment tool insertion section is configured to be arranged in the channel of the endoscope and a power reception electrode arranged to the treatment tool insertion section, wherein the power reception electrode is separated from the power transmission electrode to form a capacitor to transfer power from the power source through an electric field between the power transmission electrode and the power reception electrode to power the electrically powered treatment device.
