The stator core is configured into a cylindrical shape by abutting a laminated core that is obtained by bending and forming a rectangular parallelepiped lamination and integrating the stator core by welding. The lamination is configured by laminating a predetermined number of thin strip-shaped magnetic plates that are formed so as to have a flat rectangular shape, and in addition at least two thin sheet coupling weld portions that integrate the predetermined number of thin strip-shaped magnetic plates by welding are formed so as to extend from a first end to a second end in a direction of lamination on an outer wall surface of the lamination and so as to have a predetermined spacing in a longitudinal direction of the lamination. The stator core is formed such that an axial length A at the thin sheet coupling weld portions and a maximum axial length B between the thin sheet coupling weld portions satisfy an expression: 0.0 mm≦B·A≦0.2 mm.