There is provided a stator capable of securely preventing radial coming-out of an inter-coil insulator. A stator (5) includes: a stator core (510) having a plurality of tooth portions (512) arrayed with circumferential intervals therebetween; an insulator (530) attached to axial both end faces of the stator core (510); a coil (520) which is wound around the tooth portions (512) of the stator core (510), with the insulator (530) interposed therebetween; and an inter-coil insulator (100) placed between circumferentially mutually neighboring ones of the coil windings (520). The inter-coil insulator (100) is folded at a folding-bottom portion (102) provided so as to extend in an axial direction. The folding-bottom portion (102) is positioned on a distal end side of the tooth portions (512), and a circumferential width of the folding-bottom portion (102) is larger than a circumferential width of a slot opening (95).