an apparatus and method is disclosed for manufacturing ozone by treating oxygen or an oxygen bearing gas with uv radiation in the range of from about 130 - 170 nm . the method involves the use of cathode rays to bombard a uv emitting material which emits radiation substantially in the 130 - 170 nm range . the invention takes advantage of the fact that no radiation is generated substantially above 200 nm or below 130 nm which wavelengths tend to destroy ozone . thus , unlike the prior art , the present invention does not both make and destroy ozone , but simply makes ozone .