A linear drive device, comprising: a lead screw that is rotationally driven by a motor; a guide shaft that is disposed in parallel to the lead screw at a position eccentric from the lead screw; a base that includes a traveling surface parallel to an axis direction of the lead screw and the guide shaft, and supports the lead screw and the guide shaft; and a slider that includes a guide hole through which the guide shaft penetrates and a nut to which the lead screw is screwed, and linearly moves along the axis direction of the lead screw and the guide shaft by being guided by the guide shaft in a movement direction through rotation of the lead screw around the axis while being prevented from rotating around the axis of the lead screw, wherein the slider includes biasing means and a rolling element, the biasing means applying biasing torque along a circumferential direction with the lead screw or the guide shaft as a center, characterized in that the rolling element being disposed between the traveling surface of the base and the slider to be traveling along a surface direction of the traveling surface, transmitting, to the traveling surface, the biasing torque applied by the biasing means to the slider, and receiving reactive force of the biasing torque, in that the slider is divided into a slider body and a movable member, the slider body including the nut to which the lead screw is screwed and the guide hole through which the guide shaft penetrates, and the movable member being relatively displaceable in the circumferential direction or in a tangential direction of the circumference with respect to the slider body, a first preload spring in a compressed state is interposed between the slider body and the movable member, as the biasing means biasing the slider body and the movable member in a separating direction, and the rolling element is mounted on each of the slider body and the movable member, and in that a cylinder is provided on one of the slider body and the movable member, a piston is provided on the other of the slider body and the movable member, the piston is assembled to the cylinder to be slidable in the tangential direction, and the first preload spring is interposed between the cylinder and the piston. a lead screw that is rotationally driven by a motor; a guide shaft that is disposed in parallel to the lead screw at a position eccentric from the lead screw; a base that includes a traveling surface parallel to an axis direction of the lead screw and the guide shaft, and supports the lead screw and the guide shaft; and a slider that includes a guide hole through which the guide shaft penetrates and a nut to which the lead screw is screwed, and linearly moves along the axis direction of the lead screw and the guide shaft by being guided by the guide shaft in a movement direction through rotation of the lead screw around the axis while being prevented from rotating around the axis of the lead screw, wherein the slider includes biasing means and a rolling element, the biasing means applying biasing torque along a circumferential direction with the lead screw or the guide shaft as a center, characterized in that the rolling element being disposed between the traveling surface of the base and the slider to be traveling along a surface direction of the traveling surface, transmitting, to the traveling surface, the biasing torque applied by the biasing means to the slider, and receiving reactive force of the biasing torque, in that the slider is divided into a slider body and a movable member, the slider body including the nut to which the lead screw is screwed and the guide hole through which the guide shaft penetrates, and the movable member being relatively displaceable in the circumferential direction or in a tangential direction of the circumference with respect to the slider body, a first preload spring in a compressed state is interposed between the slider body and the movable member, as the biasing means biasing the slider body and the movable member in a separating direction, and the rolling element is mounted on each of the slider body and the movable member, and in that a cylinder is provided on one of the slider body and the movable member, a piston is provided on the other of the slider body and the movable member, the piston is assembled to the cylinder to be slidable in the tangential direction, and the first preload spring is interposed between the cylinder and the piston.