PURPOSE: To prevent poor insulation of a stator of a motor by providing recesses at junctions between laminated cores when forming the cylindrical motor stator by connecting a specified number of the laminated cores.

CONSTITUTION: After winding a coil 2 well-orderedly in high concentration round each of split laminated cores 1 of a stator of a motor, a specified number of such laminated cores 1 are joined together to form a cylindrical stator. At that time, due to the recesses 4 which are made at the junctions 5 between the laminated cores 1, a large insulation distance can be taken between the coil 2 and the laminated core even if there is a little space between insulating sections 3 formed at pole teeth of the laminated cores 1. By this method, the poor insulation of the stator of the motor can be prevented.