To provide a pilfer-proof cap with a TE cover which includes an enhanced TE function by the TE cover during distribution and with an easy separation/disposal function of a TE band in disposing.

A synthetic resin pilfer-proof cap with a TE cover includes the pilfer-proof cap having a tamper-proof function and a sealing function and a TE cover covering the outer peripheral surface of the pilfer-proof cap. The TE cover is formed in a tubular body having a predetermined height with its upper side tubular part and the lower side tubular part integrally molded. The outer peripheral surface of the tubular body is formed with a slip prevention groove. The inner peripheral surface of the upper side tubular part is welded and fixed to the outer peripheral surface of the cap body of the pilfer-proof cap. The lower side tubular part outwardly covers the break bridge of the pilfer-proof cap having a gap clearance part and the bottom end of its inner peripheral surface is formed with a tapered surface contacting the top surface of the tapered surface of a TE band for covering till the bottom end position of the TE band.