A slot die coater includes a lower die block including a first manifold in which an electrode active material slurry is accommodated, an upper die block including a second manifold in which an insulating coating solution is accommodated, and a shim plate located between the lower die block and the upper die block to form a slot communicating with a discharge port. The shim plate includes a first concave portion provided in a first surface located to cover the first manifold of the lower die block, and a second concave portion provided in a second surface located to cover the second manifold of the upper die block, wherein two second concave portions are configured to be located on opposite sides of the first concave portion in a width direction.