A linear motor includes a field core, a stator that includes a plurality of permanent magnets disposed on the field core, and an armature core that includes an armature winding wire, the armature core being disposed via a magnetic void with the permanent magnets. Assuming that a length of the armature core in a traveling direction of the linear motor is Lc, a pitch of the permanent magnets is τp, and N is a natural number, the length Lc of the armature core is specified by (N×τp−0.2×τp)≤Lc≤(N×τp+0.2×τp).