Kermanshah Petrochemical Industries Co. (KPIC) is constructing a new ammonia storage tank at Kermanshah, Iran. The new tank with capacity of 16,796 m3 has been designed according to API 620 + ANNEX R. This tank has two shells (inside diameter r = 38m, outside diameter = 40 m, height = 16,610 mm). Present report explains procedure of roof air rising of the mentioned tank that was conducted by KPIC, NDEC (Namavaran Delvar Engineering Co.) and HEDCO (Hampa Energy Engineering and Design Co) (height of air rising = 15,350 mm). After assembling the roof on the outer tank bottom, it was led to final position using air rising method. Air rising procedure allows most of the roof erection work to be constructed at a low elevation, resulting in a high quality roof as well as limiting personnel exposure to dangerous heights.