After a receiving antenna (A1) is inserted from a slot (B16) into a housing portion (B14) formed between cover members (B11, B12), the slot (B16) is pasted so as to secure the receiving antenna (A1). The receiving antenna (A1) is thus housed. Further, a tab (B17) which extends from one side of a pasted edge portion, holes (B20, B21) that penetrate opposing surfaces of the cover members (B11, B12), and perforated lines (B22, B23) running from the slot (B16) to the holes (B20, B21), respectively, are provided. Therefore, the receiving antenna (A1) can be easily attached to the antenna cover (B1) and to an outer surface of a subject (1), and the receiving antenna (A1) can be easily removed from the antenna cover (B1) and from the outer surface of the subject (1).