The present invention is to solve the problem of providing a
stator assembly device that is capable of inserting a coil into a slot without
biting into an installed insulating member in the slot when the coil is inserted into the slot from the inside of a
stator core. To solve the above problem, the
stator assembly device is provided with a leading guide member that is disposed so as to be movable in the direction of the central axis of the stator core, that by moving toward the stator core, inserts into the inside of the insulating member before the coil is inserted, in a state in which at least a portion is fitted inside the open end of the insulating member, and that is disposed in front of the moving direction of the coil that moves toward the slot. The leading guide member has a
quadrilateral shape in the length direction, has a shape that is inclined with one end portion side in the radial direction of the stator core as a vertex, and is tapered toward the front end along the center line in the radial direction of the stator core, and the vertex is disposed on the radial direction outside of the stator core.