A stator comprising: a stator core including: a yoke that extends in a circumferential direction; and teeth that protrude from the yoke in a radial direction, a slot being defined between the teeth which are adjacent to each other; an insulator that is assembled to each tooth from a tip end of the tooth, the insulator including: a main body within which the tooth is housed; and a wall that protrudes in a direction orthogonal to the radial direction from an end portion of the main body, said wall extending linearly, with an end portion in the circumferential direction contacting an inside surface of the yoke, so that the radially outer side wall of the insulator has a shape that does not follow the yoke inside surface and a triangular gap is formed between the radially outer side wall of the insulator and the yoke inside surface; a circumferentially end portion of the wall being configured to abut against the inside surface of the yoke in the slot; and a coil that is wound around the main body of the insulator; characterized by an adhesive that is attached only to a portion of the triangular gap between the yoke and the wall of the insulator, the adhesive being expandable, the adhesive being configured to adhere and fix the insulator to the stator core by expanding to fill in the triangular gap by being heated. a stator core including: a yoke that extends in a circumferential direction; and teeth that protrude from the yoke in a radial direction, a slot being defined between the teeth which are adjacent to each other; a yoke that extends in a circumferential direction; and teeth that protrude from the yoke in a radial direction, a slot being defined between the teeth which are adjacent to each other; an insulator that is assembled to each tooth from a tip end of the tooth, the insulator including: a main body within which the tooth is housed; and a wall that protrudes in a direction orthogonal to the radial direction from an end portion of the main body, said wall extending linearly, with an end portion in the circumferential direction contacting an inside surface of the yoke, so that the radially outer side wall of the insulator has a shape that does not follow the yoke inside surface and a triangular gap is formed between the radially outer side wall of the insulator and the yoke inside surface; a main body within which the tooth is housed; and a wall that protrudes in a direction orthogonal to the radial direction from an end portion of the main body, said wall extending linearly, with an end portion in the circumferential direction contacting an inside surface of the yoke, so that the radially outer side wall of the insulator has a shape that does not follow the yoke inside surface and a triangular gap is formed between the radially outer side wall of the insulator and the yoke inside surface; a circumferentially end portion of the wall being configured to abut against the inside surface of the yoke in the slot; and a coil that is wound around the main body of the insulator; characterized by an adhesive that is attached only to a portion of the triangular gap between the yoke and the wall of the insulator, the adhesive being expandable, the adhesive being configured to adhere and fix the insulator to the stator core by expanding to fill in the triangular gap by being heated.