To reduce tensile stress producing in a panel skirt part and fastening force acting on a shrink band, and suppress occurrence of implosion by making the cross section area of a metal band in the contact part on the minor axis of a cathode-ray tube different from that in the contact part on a diagonal axis, and making the cross section area on the minor axis larger than that on the diagonal axis.

A shrink band 4 is shrink-fitted to a rectangular cathode-ray tube 2 through a sticking or adhesive tape to form a band reinforcing cathode- ray tube 1. In the rectangular cathode-ray tube 2, tensile stress producing in a panel skirt part 201 is not uniform, and the tensile stress is made larger in the order of a diagonal axis J1, the major axis J2, and the minor axis J3. The shape of a shrink band 4 is formed so that width of the portion coming in contact on the minor axis J3 of the panel skirt part 201 is made larger than the width of the portion coming in contact on the diagonal axis J1 and the major axis J2. The fastening force on the minor axis J3 is made larger than the fastening force on the diagonal axis J1 and the major axis J2, and occurrence of implosion phenomenon is suppressed.