The invention relates to an inhaler for powdered, particularly medical substances, including a suction air duct that extends to a mouthpiece, a reservoir for the substance, and an at least linearly movable dosing chamber for separating a specific amount of the substance from the reservoir and placing the amount into a transfer position in order for the same to be transferred to the suction air flow. In order to further develop a generic inhaler in an advantageous manner, especially so as to charge the dosing chamber by separating a specific amount of substance from the reservoir, the dosing chamber can be rotationally moved in a superimposed fashion while being arranged eccentric to a corresponding axis of rotation.