A method of manufacturing a coil assembly unit comprises steps of coil forming, weaving, compressing steps. In the forming step, each coil wire is formed which provides linear portions and turn portions each connecting linear portions, during which bent portions are formed at both ends of each linear portion, the bent portions being bent so that mutually adjacent linear portions are deviated from each other. In the weaving step, the coil wires are mutually woven in turn, in which the turn portions intersect in turn. All the coil wires are subjected to the weaving step in turn to produce a woven coil assembly. In the compressing step, the woven coil assembly is compressed by compressing the woven coil so that each bent portion is deformed to be linear to allow the mutually adjacent linear portions to come closer to each other, thus producing the coil assembly unit.