A nasal delivery device for delivering particulate substance to the nasal airway of a subject, the delivery device comprising: a mouthpiece unit (109) which includes a mouthpiece (147) through which the subject in use exhales； a nosepiece unit (105) which includes a nosepiece (141) for fitting to a nostril of the subject； and a substance-supply unit (111) which is configured to receive a container (C) containing particulate substance and operable to provide a metered amount of substance in fluid communication with the mouthpiece and nosepiece units (109, 105), such that an exhalation air flow delivered through the substance-supply unit (111) entrains the substance； wherein the container (C) comprises first and second parts (115, 117) which together define an enclosed chamber (119) and are movable between a first, closed configuration in which the container (C) is closed and a second, open configuration in which the container (C) is open, and the substance-supply unit (111) is operable to move the first and second parts (115, 117) of the container (C) to the open configuration.L'invention concerne un dispositif d'administration nasale et un procédé d'administration d'une matière particulaire aux voies nasales d'un sujet. Le dispositif d'administration comprend : un ensemble corps comprenant une unité embout buccal qui comprend un embout buccal à travers lequel le sujet exhale, à l'utilisation； et une unité alimentation de matière qui est reliée de manière fluidique à l'unité embout buccal et peut être actionnée pour fournir une matière particulaire à administrer aux voies nasales du sujet. L'ensemble corps est conçu pour recevoir une unité embout nasal remplaçable qui comprend un embout nasal et contient un contenant renfermant une matière particulaire.
