Abstract: A stress sensor having a post (6) fixed to or integrated with the surface of an insulation substrate (1) capable of determining the direction and magnitude of a stress applied to the post (6) from changes in the characteristics of a strain gauge (2) made by a stimulus to the strain gauge (2) caused by the stress, wherein a stress to the post (6) can be converted efficiently into changes in the characteristics of the strain gauge (2). Consequently, the stress sensor has a strain gauge (2)-disposed member provided with a locally-easy-to-deform portion where the strain gauge (2) is disposed. The strain gauge (2) is a resistance element (8) and is disposed on the surface of the insulation substrate (1), the insulation substrate mainly contains a resin material, and the easy-to-deform portion is preferably a thin-wall portion (7).

Abstract: A stress sensor having a post (6) fixed to or integrated with the surface of an insulation substrate (1) capable of determining the direction and magnitude of a stress applied to the post (6) from changes in the characteristics of a strain gauge (2) made by a stimulus to the strain gauge (2) caused by the stress, wherein a stress to the post (6) can be converted efficiently into changes in the characteristics of the strain gauge (2). Consequently, the stress sensor has a strain gauge (2)-disposed member provided with a locally-easy-to-deform portion where the strain gauge (2) is disposed. The strain gauge (2) is a resistance element (8) and is disposed on the surface of the insulation substrate (1), the insulation substrate mainly contains a resin material, and the easy-to-deform portion is preferably a thin-wall portion (7).

Abstract: A temperature control signal (S.sub.1) responsive to a target temperature is biquadrated (S.sub.1.sup.4) to produce a power control signal. A power supply unit supplies electric power to one or more radiant heat sources on the basis of the power control signal, whereby an object such as, for example, a wafer is heated by radiant energy from the one or more radiant heat sources. The wafer temperature is proportional to the biquadrative root of the radiant energy in accordance with the well-known Stefan-Boltzmann's law, whereby the wafer temperature correctly follows a predetermined time-dependent target temperature variation over time.

Abstract: A heat treatment method in which a heating furnace is preliminarily heated before carrying an object to be heat-treated in the furnace and an unit heating process is repeated at least twice according to an output program for controlling an output of a heating light source which is stored in a memory so that the heat treatment is uniformly applied to every object to be heat treated.