A lens driver which moves at least one lens relative to a supporter includes a holder provided in the supporter to hold the lens to be movable in an optical axis direction, a driver configured to apply to the holder a driving force in the optical axis direction, and a position detector configured to detect a position of the holder in the optical axis direction relative to the supporter, and the lens driver including a coil provided in one of the holder and the supporter to form a straight electric path orthogonal to the optical axis direction, and a magnetic circuit provided in the other of the holder and the supporter, the magnetic circuit including a rectangular magnetic pole surface having a predetermined width to form a magnetic field orthogonal to the optical axis direction and the electric path, and being provided such that the magnetic pole surface faces the optical path.