A powder medicine administering device includes a main body, an air supply section, and a movable member slidably attached to the main body, and arranged to be moved relative to the main body from a first position through a second position to a third position. One of the main body and the movable member includes a side wall portion defining a medicine storage chamber including an opening closed by a sliding surface of the other of the main body and the movable member at the second position of the movable member, and a medicine discharge passage. The other of the main body and the movable member is formed with a medicine carrying chamber connected with the opening of the medicine storage chamber at the first position of the movable member, and connected with the medicine discharge passage at the third position of the movable member.