A tray supplier which performs supplying and collecting of trays includes a supply-side tray storage unit, a collection-side tray storage unit, a first tray placer and a second tray placer on which the trays are placed, and a first placer mover and a second placer mover which respectively move the tray placers between the supply-side tray storage unit and the collection-side tray storage unit, in which a first movement shaft of the first placer mover and a second movement shaft of the second placer mover are disposed parallel to each other, lifting and lowering units which lift or lower the first tray placer and the second tray placer are provided, and interference between the placer movers does not occur.