An energy treatment instrument (10) for an endoscope is provided with a flexible treatment instrument insertion section (11). The treatment instrument insertion section (11) is provided with a power reception electrode (141). The outer surface of the power reception electrode (141) is coated with an insulating material. The power reception electrode (141) is connected via a wire to a treatment section (12) that is positioned at the leading end of the treatment instrument insertion section (11). A cleaning section (15) is provided in the outer circumferential part of the treatment instrument insertion section (11). The cleaning section (15) is formed of an elastic material and has an outer diameter not smaller than the inner diameter of a treatment instrument channel (33) of an endoscope device (30). When an operator inserts the treatment instrument insertion section (11) into the treatment instrument channel (33), the cleaning section (15) slides within the treatment instrument channel (33) and thus extrudes foreign matters (X), said foreign matters (X) sticking to the inner circumferential surface (332)of the treatment instrument channel (33), from the treatment instrument channel (33). The power reception electrode (141) is positioned to face a power transmission electrode (341) that coats the treatment instrument channel (33) in the circumferential direction. These electrodes are capacitively coupled to form a capacitor (C1). High-frequency power is supplied to a target site (P1) of a patient (P) via the capacitor (C1) and the treatment section (12).Linvention concerne un instrument de traitement électrique (10) pour un endoscope qui est muni dune section dinsertion dinstrument de traitement (11) flexible. La section dinsertion dinstrument de traitement (11) est munie dune électrode de réception de lénergie (141). La surface externe de lélectrode de réception de lénergie (141) est revêtue dun matériau isolant. Lélectrode de réception de lénergie (141) est connect
