A stator includes a first split core having a first yoke part extending in a circumferential direction about an axis line and a first tooth extending from the first yoke part toward the axis line, a second split core having a second yoke part extending in the circumferential direction and a second tooth extending from the second yoke part toward the axis line, a first insulator arranged to surround the first tooth and having a first holding part located between a tip end part of the first tooth and a tip end part of the second tooth, a second insulator arranged to surround the second tooth and having a second holding part located between the tip end part of the first tooth and the tip end part of the second tooth, and a Hall effect sensor held by the first holding part and the second holding part.