The present invention refers to adjustable volatile substance diffuser devices, more specifically to diffusers incorporating a container with a semipermeable membrane (3, 23, 43, 63). Said membrane (3, 23, 43, 63) permits the issue of vapors but prevents the escape of liquids, with the result that an extremely clean device is achieved as the spillage of liquid is prevented in the case of inappropriate handling. The device (1, 21, 41, 61) is furthermore of very simple construction, as it is made up of two parts, a container (2, 22, 42, 62) which houses the volatile substance and a housing (4, 24, 44, 64), which supports said container (2, 22, 42, 62). The container (2, 22, 42, 62) has the membrane (3, 23, 43, 63) adhered to it. The container (2, 22, 42, 62) and the housing (4, 24, 44, 64) are coupled directly to each other and they are moved by means of guiding or articulation. The container (2, 22, 42, 62) may comprise a useful part (16), which defines the cavity (5) holding the volatile substance, and a non-useful part (6).
