According to one embodiment, there is provided armature windings of a rotating electrical machine, in which a 3-phase winding of two layers including upper and lower layers is constituted of phase belts having an electrical phase difference of 60° in between, pairs of upper coil pieces and lower coil pieces are contained in slots, the number of slots per pole per phase includes a fractional number, and a denominator thereof is an integral number greater than or equal to 4, wherein coil arrangement is carried out such that at least one coil piece in either of the upper or lower coil pieces included in two layers of upper and lower layers in one phase belt is replaced with a coil piece of an adjacent different phase.