Recent research trends on the operability of aerial displays are outlined. One problem with interface devices using aerial displays is that they do not provide haptic feedback on contact, as is the case with conventional interfaces. As a solution to this problem, technologies that provide haptic sensations at the fingertips using ultrasound, air pressure, etc. are introduced. A method of providing tactile feedback by vibration to the sole instead of the fingertips is also introduced and its effectiveness is described based on the results of evaluation experiments. Finally, future issues and developments in research on aerial image interfaces are discussed.