Well, Matcha is finely ground powder of specially grown and processed green tea leaves. What makes it so special is the tea plants are grown in shade for three to four weeks before harvest and the stems and veins are removed before processing.
This leaves (don't mind the pun) pure green tea leaf powder which is very high in antioxidants and a catechin called EGCD (epigallocatechin gallate), which is believed to have cancer-fighting effects on the body.
Matcha also contains L-Theanine which is known as the relaxation amino acid. When given to human volunteers, it caused a significant increase in alpha waves of the brain in the occipital and parietal regions, roughly 40 minutes after administration.
The increase in alpha waves produced significant relaxation int the body without any additional drowsiness or any form of impaired function.... Hey, that sounds pretty cool!
So... because it does contain caffeine you will get a boost of energy without the jitters... so you can be alert, calm and focussed through-out your day.