To provide a stator of a motor having an insulating structure achieving insulation easily and reliably. A stator (1) of a motor comprises: a teeth unit (11) with a circular cylindrical part (111) having a circular cylindrical shape and multiple projection parts (112) spaced uniformly along an outer circumference of the circular cylindrical part (111) in a circumferential direction of the circular cylindrical part (111), the projection parts (112) projecting radially outwardly from the circular cylindrical part (111); multiple bobbins (13) having cylindrical shapes with hollow sections (133) through which the projection parts (112) of the teeth unit (11) are passed to be fitted in the hollow sections (133), the bobbins (13) having outer peripheries around which windings (14) are wound; a cylindrical external unit (12) arranged radially outside the teeth unit (11) and fitted to an outer circumference of the teeth unit (11) and the outer peripheries of the bobbins (13); and multiple first insulating parts (15) arranged to fill gaps between the circular cylindrical part (111) of the teeth unit (11) and the bobbins (13) and electrically insulating the teeth unit (11) and the windings (14).