He can fire energy blasts and in later appearances he has shown the ability to become intangible.
It's not known what his full range of powers are, but his costume consists of neon colors which might suggest certain things along those lines. He fires blasts from his hands that, appropriately enough, very much resemble barrages of laser beams. He travels around on a floating platform of some sort, which he can tilt up much like a skateboard to shield from blasts.
There is the possibility that there have been several people under the mask. Mirage was active from at least 1964 until 1984.