An experiment of containerless processing was carried out by a modified floating zone technique on the ground condition using a Ba(B0.9Al0.1)(2) O-4 as a source material. In this technique, a pair of Pt tubes with different diameters was used at the upper and the lower positions, and a molten zone was formed between the two Pt tubes. Melting started from the source material near the Pt tubes and ended at the center of the molten zone. Crystallization of the molten Ba(B0.9Al0.1)(2) O-4 started from the center of the side surface of the molten zone when the supercooling was more than 250 degrees C.