In a linear motor according to this invention, the field permanent magnets 2 are arranged at an equal pitch around a field iron core 1 so that the poles are alternately changed. Also, an armature 3a on the needle side is arranged oppositely via a magnetic gap on a magnetic pole face of the field permanent magnets 2. The armature 3a consists of an armature core forming the teeth and a yoke portion by punching an electromagnetic steel plate like the comb teeth, coil being wound around a plurality of teeth 4u, 4v and 4w for this armature core to form the armature windings 5u, 5v and 5w. The teeth 6a without coil winding is disposed between teeth with coil winding 4u and 4v and between teeth with coil winding 4v and 4w. The teeth 4u, 4v and 4w with coil winding and the teeth 6a without coil winding are alternately arranged.