Ballistic one-dimensional channels are fabricated using a highly resistive region induced by focused Ga ion beam scanning. Both wide and narrow channels are fabricated using this process. Transport characteristics of these channels are controlled by a voltage applied to the Schottky electrode on the channel. The channels show multiple-step structures in their transport characteristics at low temperature when the gate voltage is varied. This is probably due to the ballistic transport through one-dimensional quantized electron states. For narrower channels, the number of the observed steps becomes fewer. Instead, the structures are observable at higher temperature.