A stator and a stator manufacturing method is provided in which a space factor can be improved, while reducing the number of components and simplifying the manufacturing process. A stator comprises a plurality of teeth cores 11 positioned at predetermined intervals on a predetermined circumference, a core back core 12 provided on a circumferential outside between adjacent teeth cores, and stator windings 13 which are wound around the teeth cores. An approximately U-shaped insulating sheet 14 is provided between adjacent teeth cores 11 with the ends of the sheet facing towards the circumferential outside, the insulating sheet 14 is provided between the teeth cores 11 and the stator windings 13, and the ends of the insulating sheet 14 are bent inward and occluded by an inner end surface of the core back core 12 which is inserted from the circumferential outside.