A coil insertion method includes winding U-phase, V-phase, and W-phase coils; inserting the U-phase, V-phase, and W-phase coils into a transfer block, such that the U-phase, V-phase, and W-phase coils are held in a plurality of holding grooves of the transfer block so as to spirally overlap, the transfer block having a columnar shape, and the holding grooves being formed in radial fashion around the transfer block so as to open from a center part of the transfer block toward an outer periphery thereof; inserting the transfer block into an inner periphery of the stator core; and pushing a side part of the coils held in the holding grooves radially outward toward predetermined slots of the stator core so that the coils are inserted from the inner peripheral side of the stator core into the slots.