Drying furnace and drying method

A drying method for drying an object by hot air using a drying furnace, the drying method comprising:

• a temperature increasing process of increasing a temperature of the object;
• a temperature measuring process of measuring a temperature of a hard-heating region having a larger heat capacity than another region in the object by a first temperature measuring part and measuring a temperature of the other region by a second temperature measuring part;
• a local heating process of locally heating the hard-heating region to a temperature approximate to the temperature of the other region by applying radiant heat to the hard-heating region of the object;
• and
• a temperature maintaining process of constantly maintaining the temperature of the object,
• wherein the object is subjected to a painting operation before being introduced into the drying furnace,
• wherein a timing for applying the radiant heat to the hard-heating region of the object in the local heating process is a timing when the temperature of the hard-heating region measured by the first temperature measuring part reaches a cross-linking temperature of a paint applied onto the object, and
• wherein the local heating by the radiant heat is applied at the timing when the temperature of the hard-heating region reaches the cross-linking temperature so that a temperature rising speed becomes larger.