An anti-insect barrier mountable on an opening (A) of a building such as a door, window, french-window or the like, to prevent insects from passing through the opening (A), the latter comprising a peripheral wall (P), the barrier (1) comprising a frame (5) mounted at the opening (A)； at least one electromagnetic waves emitter (10)； at least one ultrasonic waves emitter (11)； wherein said frame (5) has an outer face (7) facing the wall (P) of the opening (A) and an opposite inner face (8) comprising a plurality of through holes (6), said frame (5) being internally hollow to house said at least one electromagnetic waves emitter (10) and said at least one ultrasonic waves emitter (11) at said through holes (6) so that they are arranged flushed with the opposite inner face (8) of said frame (5) without protruding therefrom； so that the barrier prevents insects from passing through the opening (A) without using insect screen meshes, said at least one electromagnetic waves emitter (10) and said at least one ultrasonic waves emitter (11) being concealed from view within said frame (5).
