A linear motor equipped with a field element and an armature, the linear motor adapted to produce a force causing the field element and the armature to be relatively displaced along a given axial direction by interaction of magnetic fluxes generated between the field element and the armature during an operation of supplying electric power to the armature, comprising: a frame member defining the axial direction, the frame member having a flat dish-like shape when viewed from a first predetermined direction perpendicular to the axial direction, and is provided with a base plate having a sidewall portion in a part of a periphery thereof; a stator formed as one of the field element and the armature; a rail extending along the axial direction; a plurality of sliders mounted to the rail in a slidable manner in the axial direction while being prohibited in directions perpendicular to the axial direction; a mover formed as the other of the field element and the armature, and is provided in side-by-side relation to the stator with respect to a second predetermined direction which is perpendicular to both the first predetermined direction and the axial direction by being fixed to the sliders; a first positioning portion provided on the frame member to set a fixing position of the stator with respect to the frame member; and a second positioning portion provided on the frame member to set a fixing position of the rail with respect to the frame member in such a manner as to allow the mover to reciprocate along the axial direction with a given gap formed between the mover and the stator positioned by the first positioning portion, characterized in that the first positioning portion comprises a stator-positioning reference surface adapted to be in contact with a surface of the stator on the side of the mover so as to position the stator with respect to the frame member; and the second positioning portion is adapted to be in contact with a surface of the rail on the side of the stator so as to position the mover with respect to the frame member. a frame member defining the axial direction, the frame member having a flat dish-like shape when viewed from a first predetermined direction perpendicular to the axial direction, and is provided with a base plate having a sidewall portion in a part of a periphery thereof; a stator formed as one of the field element and the armature; a rail extending along the axial direction; a plurality of sliders mounted to the rail in a slidable manner in the axial direction while being prohibited in directions perpendicular to the axial direction; a mover formed as the other of the field element and the armature, and is provided in side-by-side relation to the stator with respect to a second predetermined direction which is perpendicular to both the first predetermined direction and the axial direction by being fixed to the sliders; a first positioning portion provided on the frame member to set a fixing position of the stator with respect to the frame member; and a second positioning portion provided on the frame member to set a fixing position of the rail with respect to the frame member in such a manner as to allow the mover to reciprocate along the axial direction with a given gap formed between the mover and the stator positioned by the first positioning portion, characterized in that the first positioning portion comprises a stator-positioning reference surface adapted to be in contact with a surface of the stator on the side of the mover so as to position the stator with respect to the frame member; and the second positioning portion is adapted to be in contact with a surface of the rail on the side of the stator so as to position the mover with respect to the frame member.