A diffuser device (100) for diffusing solutions comprises a refill (6) containing the solution to be diffused, a wick (7) disposed partially inside the refill (6) to absorb the solution, a heater (1) coupled to the refill (6) and to the wick (7) and comprising a resistance (8), able to increase in temperature when crossed by a current, for heating the wick (7) and supply means (5) able to electrically supply the resistance (8), the resistance (8) being supported by a support (20) mounted movably in the heater (1) to be able to pass, by manual operation, from a position distal to the wick (7) wherein minimum heating of the wick occurs to a position proximal to the wick wherein maximum heating of the wick occurs.