A spark-gap of the invention comprises: a first body supporting a first electrode mounting connected to a first electrode having a first electrode end, a second body supporting a second electrode mounting connected to a second electrode placed so as to face the first electrode end, and a connection arm connecting the first body to the second body. The first body and the second body have a generally cylindrical outer shape and are aligned along a common longitudinal axis. The first electrode end is offset, relative to the longitudinal axis, toward the side opposite the connection arm. The invention also relates to an electric arc generation device comprising such a spark-gap.