An insulator set including a first insulator and a second insulator for sandwiching a stator core therebetween, wherein the stator core includes a plurality of teeth that radially projects from a center portion of the stator core, the first insulator includes a plurality of first tooth covering portions that radially projects from a center portion of the first insulator, the second insulator includes a plurality of second tooth covering portions that radially projects from a center portion of the second insulator the plurality of first tooth covering portions and the plurality of second tooth covering portions cover the plurality of teeth, in a facing portion of the first insulator that faces the second insulator, a peripheral portion of the first insulator axially projects more towards the second insulator than the center portion of the first insulator, and in a facing portion of the second insulator that faces the first insulator, the center portion of the second insulator axially projects more towards the first insulator than a peripheral portion of the second insulator, and when the first insulator and the second insulator sandwich the stator core therebetween, the facing portion that faces the second insulator abuts against the facing portion that faces the first insulator, characterised in that the facing portion of the first insulator that faces the second insulator is uniformly inclined from the center portion of the first insulator to the peripheral portion of the first insulator, and the facing portion of the second insulator that faces the first insulator is uniformly inclined from the center portion of the second insulator to the peripheral portion of the second insulator. the stator core includes a plurality of teeth that radially projects from a center portion of the stator core, the first insulator includes a plurality of first tooth covering portions that radially projects from a center portion of the first insulator, the second insulator includes a plurality of second tooth covering portions that radially projects from a center portion of the second insulator the plurality of first tooth covering portions and the plurality of second tooth covering portions cover the plurality of teeth, in a facing portion of the first insulator that faces the second insulator, a peripheral portion of the first insulator axially projects more towards the second insulator than the center portion of the first insulator, and in a facing portion of the second insulator that faces the first insulator, the center portion of the second insulator axially projects more towards the first insulator than a peripheral portion of the second insulator, and when the first insulator and the second insulator sandwich the stator core therebetween, the facing portion that faces the second insulator abuts against the facing portion that faces the first insulator, characterised in that the facing portion of the first insulator that faces the second insulator is uniformly inclined from the center portion of the first insulator to the peripheral portion of the first insulator, and the facing portion of the second insulator that faces the first insulator is uniformly inclined from the center portion of the second insulator to the peripheral portion of the second insulator.