Abstract: A negative pressure type drying machine includes a wheeled machine base carrying an drying chamber that has the peripheral walls respectively formed of high transmittance glasses, a hygrometer/thermometer for measuring the temperature and humidity in the drying chamber, an electric heater mounted in the drying chamber at the bottom for heating the air inside drying chamber, a high pressure blower for drawing air out of the drying chamber to produce a negative pressure in the drying chamber, and a control system mounted in the wheeled machine base below the drying chamber for controlling the operation of the electric heater and the high pressure blower.