The development of an automatic rice checker for measuring rice quality, in terms of moisture content, bulk density, and milling yield, has been getting much attention. The machine corrects human subjective judgment in grading paddy that is purchased from rice growers by rice mills or farmers' associations in Taiwan. The dimensions of the automatic rice checker, developed in 1992, are 1150 x 800 x 1966 mm. It consists of rice huller, moisture meter, weighing device, pneumatic sorter, air compressor, vertical conveying system with a bucket, actuator, and power screw, and microprocessor. It takes about 1 min and 30 s to complete the whole process, including two replications of hulling. The data of moisture content, weight of paddy and brown rice, and milling yield (ratio of brown rice to paddy) are shown on the display panel and then transmitted to a PC through RS-232C for further data processing. The automatic rice checker is designed for local farmers associations, to avoid human bias in inspecting and grading the dried paddy that is handed in by rice growers. After several tests, the rice checker has proved to be accurate and efficient. The manufacturing cost of the rice checker is about US$ 5 000.