A card reader use in a higher-level device may include a card transfer path; a card insertion detecting mechanism; a transfer roller; a turn detecting mechanism structured to detect a turn of the transfer roller; a card detecting mechanism; and a control unit. The control unit structured such that, if the card detecting mechanism switches from the OFF situation to the ON situation after the card insertion detecting mechanism switches from the OFF situation to the ON situation, even though no turn of the transfer roller is detected by the turn detecting mechanism, the control unit of the card reader sends a control unit of the higher-level device an alarm signal for notifying that a skimming device has been inserted through the insertion slot.