To provide a method of disinfecting and drying plant seeds in which seeds can be dried in high heat efficiency for a shot time, as the plant pathogenic microbes sticking to the seeds are disinfected safely to human bodies without adverse effect on the germination and the like.

The drying chamber is kept at a reduced pressure by controlling the aspiration from the outside and the exhaustion toward the outside, the seeds are fed thereto batchwise or continuously and the seeds are radiated with far-infrared rays from far-infrared heaters, while the air heated with the far-infrared rays is forcedly circulated in the drying chamber whereby the seeds are brought into contact with the circulated air flow and disinfected and dried.