To shorten time for applying high frequency to timber as much as possible, thus, further prevent cracks generated inside the timber, and reduce cost.

This timber drying method includes: a primary drying process 1 of drying timber so that the water content of the timber becomes 25-40 W%; a heat treatment process 10 of performing high frequency heating of the timber at 95-130°C, preferably at 100±2°C for 20-60 minutes, preferably 30-40 minutes after the primary drying process 1; and a secondary drying process 20 of curing and drying the timber so that the water content becomes 20 W% or less after the heat treatment process 10.