The invention relates to a scent diffuser (1) comprising a housing (2) having openwork parts (5), a substrate (6) housed inside the housing (2) and in which a fragrant substance or composition is adsorbed or absorbed, and means (7) for keeping the substrate (6) inside the housing (2). The housing (2) comprises a bottom (3) and a cover (4), one of the openwork parts (5) of the housing (2) is formed in the bottom (3) and the other is formed in the cover (4) of the housing (2), the substrate (6) is a block (61) provided with through-openings (62) through which an air flow that passes through the housing (2) is able to pass, and the means (7) for keeping the substrate (6) inside the housing (2) comprise first holding means (711, 712) made in one piece with the housing (2) and second holding means (721, 722) made in one piece with the substrate (6).
