An improvement on the structure of a measuring tape device is that a magnetic mechanism is secured at the distal end of a measuring tape. The magnetic mechanism is not placed onto the leg piece of the hook member and thus is not formed as part of the body of the hook member of the measuring tape. The front end of the magnetic mechanism is placed in alignment with the “0” cm mark on the measuring tape. During measuring process of an object of measurement and a designated point, the magnetic mechanism allows the measuring tape to be magnetically attached to the surface of the object and anchored at the exact starting point of measurement, and therefore, the measuring precision will not be skewed because of thickness of the hook member or because of the gap caused by the movable mechanics of the hook member.