The present invention provides a linear motor device that can reduce a variation in thrust caused by a variation in attractive force. The linear motor device includes a linear motor 1 and a control section 30 that controls the linear motor 1. The linear motor 1 includes a magnet member 2 composed of permanent magnets having respective N poles and S poles alternately arranged in an axial direction, and a coil member 3 which is located orthogonally to the axial direction with respect to the magnet member 2 and through which the magnet member 2 is movable in the axial direction relative to the coil member 3. The control section 30 controls current conducted through the coil member 3 so that a moving one of the magnet member 2 and the coil member 3 reciprocates within a use range L corresponding to a part of a pitch p between the magnetic poles N and S in the magnet member 2.