the card reader includes a main body 40 having a card passage 40 a , a magnetic head for reading the information recorded on a card 30 , an opening 42 provided in a card passage 41 of the main body 40 , and an elastic member 100 for biasing the magnetic head 70 from an outward position to an inward position of the card passage 41 through the opening 42 . invasion preventing member 50 , provided in close contact with the circumference of the magnetic head 70 , is brought into contact with the main body 40 . as a result , invasion of foreign material into the card reader main body circuit unit 110 including the magnetic head 70 from the outside is prevented .