Thank you for your comment.
The first episode should answer some of your questions. Yes, antimatter can be created in particle
accelerators. Anti protons and positrons (= anti electrons) are produced and assembled to form anti-hydrogen. I read that recently anti-helium nuclei have been manufactured too. Up to now, nothing heavier has been synthesized (like anti-oxygen) or even observed. I'll discuss of the likely-hood of observing anti-atoms in a future episode.
And if you breathed anti-oxygen, I think you wouldn't feel too well afterwards ;-).
Antimatter exists also naturally. Most of it is under the form of positrons that occurs from beta decays of protons into neutrons (Proton --> Neutron + neutrino + positron). It is also found in cosmic rays.
Thank you for answering my queries..I guess in near future North Korea would be bragging about their new invention 'Anti-Matter Bomb' that may outpower the mightiest bombs of other nations!
No worries, antimatter is ultra expensive to create, around 60 trillion dollars a gram...