A coil block for low-pass filtering high-band components of a pulse width modulation signal, comprising: a first coil; a second coil; a core on which the first coil and the second coil are wound, the core having an intermediate layer located between the first coil and the second coil and arranged to separate the first coil and the second coil from each other; and a shield for shielding the first coil, the second coil, and the intermediate layer; wherein the shield is attached to a portion of the core; characterized in that the coil block is configured wherein: if directions of current being applied to the first coil and the second coil are different from each other, a direction of magnetic force induced by the first coil is equal to a direction of a magnetic force induced by the second coil, and if a direction of current being applied to the first coil and the second coil are equal to each other, a part of the magnetic force generated by the first coil is interrupted by the intermediate layer and a part of the magnetic force generated by the second coil is interrupted, another part of magnetic forces generated by the first coil and the second coil are applied in a space between the shield and the intermediate layer so that the part of the magnetic force from the first coil and the part of the magnetic force from the second coil are offset in this space. a first coil; a second coil; a core on which the first coil and the second coil are wound, the core having an intermediate layer located between the first coil and the second coil and arranged to separate the first coil and the second coil from each other; and a shield for shielding the first coil, the second coil, and the intermediate layer; wherein the shield is attached to a portion of the core; characterized in that the coil block is configured wherein: if directions of current being applied to the first coil and the second coil are different from each other, a direction of magnetic force induced by the first coil is equal to a direction of a magnetic force induced by the second coil, and if a direction of current being applied to the first coil and the second coil are equal to each other, a part of the magnetic force generated by the first coil is interrupted by the intermediate layer and a part of the magnetic force generated by the second coil is interrupted, another part of magnetic forces generated by the first coil and the second coil are applied in a space between the shield and the intermediate layer so that the part of the magnetic force from the first coil and the part of the magnetic force from the second coil are offset in this space. if directions of current being applied to the first coil and the second coil are different from each other, a direction of magnetic force induced by the first coil is equal to a direction of a magnetic force induced by the second coil, and if a direction of current being applied to the first coil and the second coil are equal to each other, a part of the magnetic force generated by the first coil is interrupted by the intermediate layer and a part of the magnetic force generated by the second coil is interrupted, another part of magnetic forces generated by the first coil and the second coil are applied in a space between the shield and the intermediate layer so that the part of the magnetic force from the first coil and the part of the magnetic force from the second coil are offset in this space.