The disclosure discloses a linear motor comprising: a field system in which a plurality of permanent magnets are linearly arranged: and an armature configured to face said field system and to have an armature core provided with armature windings, said linear motor running along a predetermined direction of travel with either said field system or said armature serving as a mover and the other serving as a stator, wherein: said armature core comprises: auxiliary teeth that are respectively provided on both ends along said direction of travel and around which said armature windings are not wound; and a plurality of main teeth that are provided between said auxiliary teeth, and each of said auxiliary teeth comprises an end portion shape in which a dimension in a teeth height direction orthogonal to said direction of travel is variable along said direction of travel.