The invention relates to a linear motor which is provided with a row of permanent magnets 6a, 6b, 6c, . . . for a field system, and an armature 2 facing the same via a magnetized space in an orthogonal direction thereto, wherein the armature core 3 has a winding accommodation groove 3a formed at both sides of armature iron plates produced by punching out oriented electromagnetic steel plate so as to become rectangular, and convex and concave engagement portions 3b and 3c, the armature iron plates are laminated to constitute one core block, and at the same time, the lengthwise direction, orthogonal to the permanent magnet row, in the respective core blocks is made the same as the rolling direction of electromagnetic steel plates. Thereby, since the magnetic flux of the armature winding 4 flows along the rolling direction of the core blocks, the magnetic flux density can be increased, and the peak thrust can be also increased.