To provide a device for acquiring alkali metal and alkaline earth metal by using solar heat as an energy source.

The device is installed with a parabola type condenser 1 opened with a hole in a bottom top part, a sub-mirror 2 installed in a focal point neighborhood of the condenser 1, and a heat resistant crucible 5 in a course passing solar light reflected by the sub-mirror 2 through the hole 4 of the bottom top part of the condenser 1 and in a rear side of the condenser 1. Solar light is reflected by a concave of the parabola type condenser 1, it is condensed at the focal point, it is guided to the rear side of the condenser 1 through the hole opened in the bottom top part of the condenser 1, the heat resistant crucible 5 holding a melting reception object is installed in a place in the course, and the melting reception object is melted by solar heat. Alternately, a reflecting mirror is provided in the course of solar light, and reflected light of the reflecting mirror is irradiated on the heat resistant crucible to melt the melting reception object. The molten object is electrolyzed as it is to acquire alkali metal and alkaline earth metal. The melting reception object is a chloride or its mixture of alkali metal and alkaline earth metal.