To obtain an analytical method in which a composition composed of a ceramic and of an amphoteric metal can be analyzed with high accuracy by applying an emission analytical method to a sample solution obtained in such a way that the composition is pulverized and that it is heated and melted inside a crucible together with an alkali flux so as to be changed into a solution by using an acid.

A discal sample whose diameter is 65mm and whose thickness is about 1mm is pulverized so as to be easily dissolved into a solution. Since the hardness of a sample which contains a ceramic is high, a pulverizing container made of tungsten carbide is used, and the sample is pulverized by a vibrating mill. The mesh of a sieve is selected so as to aim at about 60 meshes. The pulverized sample is dried at about 105°C for about two hours in order to remove its adsorbed moisture, and it is cooled down to room temperature in a desciccator. The amount of the sample to be analyzed is sampled in a range of about 0.1 to 0.5g, one gram of sodium hydroxide as a flux is put into a nickel crucible, and the sample is heated and melted by using a gas burner. As a temperature for heating, about 600 to 800°C is selected. After the sample has been melted, the whole amount is set at 200ml, and the sample solution for plasma emission analysis is obtained.