It is not known who has made the first masks or even when or why, maybe it was to disguise themselfs while hunting or to frighten their ememy on the battlefield.
The earliest known reference to mask use is found in a southern France cave. It is to believed to have been painted around 20,000 BC. The art depicts a human masked in deer skin and antlers.
In religious rituals they have been used to insure a good harvest or a safe hunt or to ward off evil. Some cultures believe that the person wearing a mask is transformed into the character of the mask.
The earliest dramatic use of masks that we know about was in Greece. Masked singers and dancers represented the gods, satyrs, and other mythical beings.
Over four thousand years ago the early Chinese made terrifying and ferocious clay masks with fangs and gaping mouths which represented demons and monsters, creatures of the spirit world.
Half masks, covering the eyes and nose were used by Italian clowns in the 1500's. They are still seen at masquerade parties and costume balls.
Super heroes such as Spider-man, Zorro and Batman wore masks.
Many sports such as baseball, fencing, hockey, etc... wear protective masks.

*MASK - n. (Fr. masque, a mask, visor, Ar. maskharah, a buffoon.)
1. A covering for the face or part of the face to conceal or disguise the identity.
2. Anything that conceals or disguises; as, a mask of snow on the ground.
3. A party, carnival, etc. where masks are worn; a masquerade: often spelled masque.
4. A person wearing a mask; a masker.
5. A likeness of a person's face, or face and neck; specifically, (a) a sculptured or molded likeness of the face; as, a death mask is a cast of the face made soon after death; (b) a grotesque or comic representation of a face worn to amuse or frighten, as at Halloween; a false face; (c) a sculptured head or face, often grotesque, used as an ornament on a building, gargoyle, etc.; (d) a figure of a head worn on the stage by an ancient Greek or Roman actor to identify a character and amplify the voice.
6. A protective covering for the face or head, as a wire screen, metal shield, or respirator (gas mask).
7. The face or head of a fox, dog, etc.
8. Something serving to conceal artillery, military operations, etc. from observation; a piece of camouflage.
9. An opaque border used to cover unwanted parts of a photograph or to alter it's shape.
10. A masque. (see definitions 1. and 2.)
11. In zoology, a masklike formation about the head, as the enlarged lower lip of a dragonfly larva.
"The Man In The Iron Mask" a noted prisoner of state during the reign of Louis XIV, who wore a black mask which was never removed in the presense of any one, and whose identity has ner been definitely established.
*Reference, my old 1979
WEBSTER'S NEW UNIVERSAL UNABRIDGED DICTIONARY