HEAT TREATMENT METHOD AND HEAT TREATMENT APPARATUS

PROBLEM TO BE SOLVED: To provide a heat treatment method and a heat treatment apparatus capable of performing light irradiation heating of a workpiece, without damaging a resin contained in the workpiece.SOLUTION: Between a holding plate 20 and a flash lamp FL in a chamber 10, an optical filter 60 for cutting ultraviolet light having a wavelength of 400 nm or less is disposed. When the flash light emitted from the flash lamp FL passes through the optical filter 60, ultraviolet light in a wavelength region of 400 nm or less is cut. A processed workpiece 8 is composed by laminating a functional layer on the upper surface of a resin substrate. By irradiating the workpiece 8 with the light, obtained by cutting ultraviolet light having a wavelength of 400 nm or less from the flash light having an extremely short irradiation time, desired heat treatment can be carried out by raising the temperature only of the functional layer up to a required processing temperature, without giving a damage due to ultraviolet light and a thermal damage on the resin substrate.