A card reader includes a shutter provided at a card insertion port, a shutter opening and closing detection device for detecting the shutter being opened and a control device for taking the card shaped medium into the inside of the card reader. In a waiting state where the shutter is closed and a card shaped medium is not present in the inside of the card reader and further, when the shutter opening and closing detection device detects opening of the shutter without detecting insertion of a card shaped medium from the card insertion port, the control device decides occurrence of abnormality to perform abnormality coping processing.