In a component mounting work area (200), two electronic circuit boards (2) are placed in zigzag and components are mounted independently on each board. Two sets of working heads (4, 14), their drive units, board conveying/holding devices (3, 13), recognition cameras (9, 19), and so forth are arranged. The board conveying/holding devices for holding boards are moved to positions close to component feed units and components are mounted in respective mounting areas. <IMAGE>