According to an embodiment, a nozzle of an additive manufacturing device includes a first inner surface that defines a first path through which an energy ray passes; and a second inner surface that defines a second path that extends along the first path and through which gas and a powder material pass. The first path opens to a leading end of the nozzle. The second path opens to near or around the first path. At least part of the second inner surface includes a first region having a larger friction coefficient for the powder material than the friction coefficient of at least one of the first inner surface and an outer peripheral surface of the leading end.