To provide a manufacturing method of a core for common mode choke coil, with which heat treatment without deterioration of impedance even if resin is impregnated and with less deterioration of impedance even in a high temperature storage test is performed, and to provide the common mode choke coil core and a coil, which are manufactured by the method.

In the manufacturing method of the core for common mode choke coil, in which resin is impregnated in a winding magnetic core formed of a nano crystal alloy thin band, a Fe basis soft magnetic alloy thin band is wound and is made to be the magnetic core. Heat treatment for nano-crystallizing the winding magnetic core in an atmosphere whose oxygen concentration is 20 ppm to 100 ppm is performed, and resin is impregnated in the winding magnetic core on which heat treatment is performed.