<；P>；PROBLEM TO BE SOLVED: To provide an air conditioning system capable of carrying out sterilization and deodorization in air by an oxygen radical produced by ozone decomposition while making ozone concentration as low as possible in a space to be air-conditioned. <；P>；SOLUTION: The air conditioning system 1 is constituted to supply air which is conditioned by an air conditioner 10, into the space 11 to be air-conditioned via an air supply duct 12 and to return the air exhausted from the space 11 to be air-conditioned to the air conditioner 10 via a return air duct 13. An air filter 20 built in the air conditioner has an ozonolysis catalyst 36 arranged in close contact with the upstream side of a medium performance filter 37 having dust collecting efficiency of 60% or more in a colorimetric method, and the air conditioner is provided with an outside air duct for taking in outside air. <；P>；COPYRIGHT: (C)2008,JPO&INPIT
