A Voice Coil Motor comprising: a base unit; a bobbin having a rotation prevention unit; a coil disposed on the bobbin, a yoke comprising an upper plate, a lateral plate extending from the upper plate and an inner unit extending from the upper plate, a magnet oppositely disposed to the coil; and an upper elastic member disposed on an upper surface of the bobbin, wherein the inner unit of the yoke is configured to be hitched by the rotation prevention unit to prevent rotation of the bobbin, wherein a first gap is formed between a lateral surface of the rotation prevention unit and a lateral surface of the inner unit of the yoke facing the lateral surface of the rotation prevention unit, the magnet comprises four magnets disposed on four corners of the yoke, respectively, the rotation prevention unit comprises a plurality of rotation prevention units, and wherein the inner unit of the yoke comprises a plurality of inner units, characterized in that a recess portion is formed in a shape of a staircase having a first depth from an upper surface of the rotation prevention unit, and a second depth formed from the lateral surface of the rotation prevention unit, a second gap is formed between a lateral surface of the recess portion and the lateral surface of the inner unit of the yoke, the second gap is greater than the first gap, the recess portion is configured to reduce a contact area between the rotation prevention unit and the inner unit of the yoke by the first depth of the recess portion, and the bobbin is protrusively formed at a periphery with the plurality of rotation prevention units along the periphery of the bobbin, where four rotation prevention units are formed along the periphery of the bobbin, each spaced apart at a predetermined distance. a base unit; a bobbin having a rotation prevention unit; a coil disposed on the bobbin, a yoke comprising an upper plate, a lateral plate extending from the upper plate and an inner unit extending from the upper plate, a magnet oppositely disposed to the coil; and an upper elastic member disposed on an upper surface of the bobbin, wherein the inner unit of the yoke is configured to be hitched by the rotation prevention unit to prevent rotation of the bobbin, wherein a first gap is formed between a lateral surface of the rotation prevention unit and a lateral surface of the inner unit of the yoke facing the lateral surface of the rotation prevention unit, the magnet comprises four magnets disposed on four corners of the yoke, respectively, the rotation prevention unit comprises a plurality of rotation prevention units, and wherein the inner unit of the yoke comprises a plurality of inner units, characterized in that a recess portion is formed in a shape of a staircase having a first depth from an upper surface of the rotation prevention unit, and a second depth formed from the lateral surface of the rotation prevention unit, a second gap is formed between a lateral surface of the recess portion and the lateral surface of the inner unit of the yoke, the second gap is greater than the first gap, the recess portion is configured to reduce a contact area between the rotation prevention unit and the inner unit of the yoke by the first depth of the recess portion, and the bobbin is protrusively formed at a periphery with the plurality of rotation prevention units along the periphery of the bobbin, where four rotation prevention units are formed along the periphery of the bobbin, each spaced apart at a predetermined distance.