To provide a separator tape for an insulating tape, having high hygroscopicity as a separator tape of the insulating tape that is wound as a reinforcing insulating layer in a cable connecting portion, and then molded in heating mold.

This separator tape is wound as a reinforcing insulating layer in a cable connecting portion and then molded in heating mold. A hygroscopic material is blend with a base resin of this separator tape, or the separator tape is formed of the hygroscopic material. Thus, taking of unnecessary moisture amount into the cable connecting portion is effectively reduced, occurrence of voids (bubbles) due to moisture in the cable connecting portion can be reduced, and the high quality cable connecting portion having superior insulating characteristic can be provided.