To provide a method for drying a plant raw material capable of releasing a water content contained in a timber in a short time by effectively removing especially a rubber substance in the timber.

The method for drying the plant raw material comprises the steps of passing the raw material through an oil at a high temperature the soften, the rubber substance contained in a capillary of the raw material making part of it go out, evaporating the water content contained in a fiber of the raw material by heat, further dissolving and releasing the rubber substance in the capillary of the raw material with boiled water and forming the raw material in a specific shape with water at an ordinary temperature. Lastly, the rubber substance on the surface is removed, and dried to completely release the water content of the raw material. The water content is released off from the treated raw material in a short time. As compared with a conventional treating method comprising the step of drying in the shade for several years, there is all the difference in efficiency of the treatment. In using the raw material in the industrial fields, not only a time can be shortened but also a problem such as a space for storing the raw material can be solved.