A linear motor unit comprising a first linear motor and a second linear motor which are adjacent to each other, each having: a stator; a movable element that linearly reciprocates along the stator; a magnetic sensor configured to detect a position of the movable element; a frame member that accommodates the stator, the movable element, and the magnetic sensor, wherein the first linear motor and the second linear motor are arranged so that each of the first linear motor and the second linear motor align with a same position with respect to a moving direction of the movable element thereby the first linear motors and the second linear motors are integrated as a unit in a state of alternate arrangement and used as the linear motor unit; characterized in that: the frame member includes a sensor fixing portion that fixes the magnetic sensor so that the magnetic sensor can be displaceable with respect to the moving direction of the movable element to be arranged and fixed; a linear scale that is fixed to the moveable element and storing information specifying a position of the movable element and origin point signal information indicating an index mark; each of the magnetic sensors includes a detection element that detects a magnetic signal marked with the linear scale, and a bias magnet for preventing the noise generated in a detection process of the detection element; each of the magnetic sensors of the first linear motor and each of the magnetic sensors of the second linear motor are disposed so as to be placed in mutually different positions without overlap region with respect to the moving direction of the movable element; the linear scale of the first linear motor and the linear scale of the second linear motor are respectively fixed to the movable elements in a position opposite the respective magnetic sensors; and the origin signal information on the linear scale of the first linear motor and the origin signal information on the linear scale of the second linear motor are marked at mutually different places so that each of which corresponds to the position of the magnetic sensor. a stator; a movable element that linearly reciprocates along the stator; a magnetic sensor configured to detect a position of the movable element; a frame member that accommodates the stator, the movable element, and the magnetic sensor, wherein the first linear motor and the second linear motor are arranged so that each of the first linear motor and the second linear motor align with a same position with respect to a moving direction of the movable element thereby the first linear motors and the second linear motors are integrated as a unit in a state of alternate arrangement and used as the linear motor unit; characterized in that: the frame member includes a sensor fixing portion that fixes the magnetic sensor so that the magnetic sensor can be displaceable with respect to the moving direction of the movable element to be arranged and fixed; a linear scale that is fixed to the moveable element and storing information specifying a position of the movable element and origin point signal information indicating an index mark; the frame member includes a sensor fixing portion that fixes the magnetic sensor so that the magnetic sensor can be displaceable with respect to the moving direction of the movable element to be arranged and fixed; a linear scale that is fixed to the moveable element and storing information specifying a position of the movable element and origin point signal information indicating an index mark; each of the magnetic sensors includes a detection element that detects a magnetic signal marked with the linear scale, and a bias magnet for preventing the noise generated in a detection process of the detection element; each of the magnetic sensors of the first linear motor and each of the magnetic sensors of the second linear motor are disposed so as to be placed in mutually different positions without overlap region with respect to the moving direction of the movable element; the linear scale of the first linear motor and the linear scale of the second linear motor are respectively fixed to the movable elements in a position opposite the respective magnetic sensors; and the origin signal information on the linear scale of the first linear motor and the origin signal information on the linear scale of the second linear motor are marked at mutually different places so that each of which corresponds to the position of the magnetic sensor.