PURPOSE: To efficiently and accurately wind an insulator tape around a tortoise- shell-shaped coil for an electric motor or the like, by dividing the wound area of the coil into four and automating the winding of the tape around most of the area.

CONSTITUTION: A tape 3 is automatically wound around the regions A, A' of a tortoise-shell-shaped coil 2 and separately wound around the other regions B, B'. To wind the tape 3 around the regions A, A', the tape is first bonded to a point (a) and then moved at an appropriate speed toward another point (b) while the tape is supplied and revolved around the coil 2. As a result, an overlapped tape layer is made. When the tape 3 has reached the point (b), the revolution and movement of the tape 3 are stopped. The tape is 3 is then moved in the opposite direction from a point (c) to another (d) as the revolution of the tape remains stopped. Such operations are repeated to wind the tape 3 up to a point (f). After that, the tape 3 is manually wound around the regions B, B' by a conventional tape winder.