Slow evaporation as a crystallization technique can allow the growth of large oriented crystals. In the experiments performed, sodium chlorate crystals were obtained by evaporating microdroplets of a saturated aqueous solution both at ambient conditions and at a constant temperature of 31.5ºC in a closed container. The solution was saturated at a temperature of (31.5±0.1)ºC. A 5 μL drop of the solution was placed on silicon wafers to evaporate slowly. To determine the effect of magnetic field on crystallization, experiments were performed under zero-field conditions and in a static magnetic field of B=(390±5) mT. Preliminary research results show that larger and more regularly shaped macrocrystals are formed by slow evaporation in a closed system at constant temperature in the applied magnetic field.