Disclosed are apparatus and method for ultrasonically dispersing a silica sol such as is used in a process of manufacturing a silica glass by a sol-gel method. The apparatus includes a sol feeder for holding a sol to be dispersed, a sol container for containing the ultrasonically dispersed sol, a medium tank having a liquid-phase ultrasonic medium, an ultrasonic vibrator for generating ultrasonic waves within the tank, and a sol pipe for providing a sol feeding path connecting the sol feeder and the sol container to each other, the sol pipe having a portion submerged under the ultrasonic medium in the medium tank. The portion of the sol pipe submerged under the ultrasonic medium has a shape bent in a zigzagged fashion.