Abstract: This invention relates to an electromechanical barrier, which comprises a movable bar (10) fixed and turning with a shaft (14) supported in a body, and at least one spring balancing means to balance the bar during its movements between an open and closed positions. A secondary shaft (20) is housed in the body parallel to the bar rotating shaft (14), a driving gear (21) couples the bar rotating shaft (14) to said secondary shaft (20) so that one turn of the former corresponds to one turn in proportion of the latter, and said at least one spring balancing means (22) is connected with said secondary shaft (20).