An electrosurgical instrument includes mutually movable instrument legs each comprising one or more electrode faces between which tissue can be clamped and treated in electrothermal manner. The movement of the instrument legs relative to each other can be delimited by at least two spacers which are spaced from each other in the longitudinal extension of the instrument legs and act on the instrument legs. At least one electrode face portion subjected to deflection in a closed position of the instrument legs is formed to be bow-shaped, in particular concave, the curvature being contrary to the bending direction to be expected.