We developed 3 models of riding-type, fully automatic vegetable transplanters. These prototypes are suitable for cell mold seedlings and pulp mold cell pot seedlings, mainly of leaf vegetables such as cabbage, Chinese cabbage, and lettuce. The prototypes enabled continuous transplanting work on 2 rows simultaneously, a planting speed of 60 cells/row/min, with vegetable seedlings fed automatically. The transplanting accuracy, in terms of the rate of misplanted hills, was 3% or less, and the working capacity per worker was approximately 10 a/h. We estimated that the annual coverage area of this machine for cultivating cabbage is 53 ha/year, and the minimum economically suitable area for use is 8.2 ha. Based on these prototypes, transplanters have been put on the market by several companies and are now being used in various areas. In this study, we presented a draft of the standards for seedling trays, such as cell mold seedling trays and pulp mold cell pots (paper pots), for possible use of a fully automatic vegetable transplanter. At present, 4 million or more trays are supplied to the market.