A stator includes: a plurality of stator pieces around which coils are wound; a stator holder which supports the plurality of stator pieces by arranging the plurality of stator pieces in a peripheral wall portion in an annular shape; and a housing which is disposed on an outer side of the stator holder to support the stator holder, wherein the stator holder includes a flange portion which continuously protrudes outward in a radial direction thereof from an edge of one end side in an axial line direction thereof and is fixed to the housing, and a reinforcing portion which suppresses vibration in the radial direction of the stator holder on an outer peripheral surface of the peripheral wall portion.