To provide a composition analyzer or the like which can highly accurately analyze the composition of even an analysis object of a minute amount.
A solution 96 is dropped to a surface 28a of a reflecting plate 28. The surface 28a of the reflecting plate 28 is constituted of an excessively water-repellent plating coating 28b. Therefore, the dropped solution 96 is shaped close to a sphere and an adhesion area to the reflecting plate 28 becomes considerably small. An area of a sample 34 obtained by vaporizing a solvent from the solution 96 becomes considerably small as well. If an amount of an adhering substance 92 included in the dropped solution 96 is equal, the sample 34 is made considerably thicker than in the prior art. The composition can be highly accurately analyzed even when the amount of the adhering substance 92 is small.