A method of joining terminals by soldering is provided which allows control of increasing gas supply even in soldering performed in a gas atmosphere within a gas chamber. The ester is produced by a transesterification reaction in which a starting material ester and an alcohol are brought into contact with a solid acid catalyst that displays the characteristics of a very strong acid in terms of the absolute value of argon adsorption heat ranging from 15 to 22 kJmol. The thermal conduction vacuum gauge using a Peltier tip has a simple structure, and is of micron size, and operates at high sensitivity over a wide range of pressure, thereby enabling the measurements of a pressure at higher resolution than existing thermal conduction gauges while facilitating local pressure measurements. Other embodiments include those in which the solvent comprises methanol, or the treatment solution further comprises a silver salt, one or more organic acids, an anti-inflammatory agent, and a hydrogel. The holding pin which is on the upper side from the center of the wafer in the planar direction of the inclined wafer is the second holding pin, and the angle of inclination of the side face of the second holding pin at a position where ions are implanted into the wafer has an angular degree which is equal to or less than an angle of incidence of the ion beam relative to the wafer. One of the first layers on its surface remote from the second layer has a surface profile forming an arrangement of a plurality of first micro-lenses.