A plant factory includes a first water tank, a plurality of second water tanks and a third water tank. The manufacturing method includes: planting a first growth stage plant on a first planting tray, and placing the first planting tray in the first water tank； repeating the previous step for several times so that the first planting trays are placed in sequence in the first water tank ； transferring the plants grown to a second growth stage to a plurality of second planting trays, and placing the second planting trays in the second water tanks to allow the plants to grow to the third growth stage； placing the second planting trays in the third water tank when the plants grow to a third growth stage so that the roots of the plants are dipped in water or diluted nutrient solutions, and lighting the plants to harvest. As such, the efficiency of planting can be effectively increased, and the productivity of a land per unit can also be increased.一種植物工廠，包含有一第一水槽、複數個第二水槽及一第三水槽，其生產方法之步驟括：於第一栽植盤上種植第一成長階段之植物，將該第一栽植盤置於第一水槽；重複前步驟數次，使第一栽植盤依序排列於第一水槽；將成長至該第二長成階段的植物移株至複數個第二栽植盤，並將該些第二栽植盤置放至該些第二水槽，讓植物成長至第三成長階段；於植物成長至第三長成階段時，將第二栽植盤移至第三水槽中使植物根部泡水或稀釋的營養液並照光後進行採收。藉此，有效增進作業的效率，並且提升每單位土地的產能。
