A substrate conveyor-positioner unit for conveying and positioning a substrate in an X direction is arranged on a supporting base. Supporting frames are arranged in a standing manner on both ends in a Y direction being orthogonal to the X direction on the supporting base. A component supplying unit is arranged on at least one end side in the Y direction on the supporting base. A plurality of Y-axis tables is laid between upper ends of the both supporting frames at an appropriate interval. An X-axis table is attached to a movable portion of each Y-axis table. An operating head for holding a component by suction at the component supplying unit and for mounting the component on the substrate on the substrate conveyor-positioner unit is attached to a movable portion of the X-axis table. Moreover, a height of upper ends of the supporting frames is located below eyes of a worker to enable the worker to visually confirm conditions of mounting operations.