A stator includes a stator core and an insulator. The insulator includes a main body and a wall. An adhesive is attached to a portion of a triangular gap between the wall of the insulator and a yoke of the stator core. The adhesive is expandable, and adheres and fixes the insulator to the stator core by expanding to fill in the gap by being heated. Also, a stator manufacturing method includes attaching an adhesive to the wall of the insulator or an inside wall of the yoke, installing the insulator on a tooth, and heating the stator core and the insulator.