The estimation of microbiological contamination of air in the building of cocoa powder producing factory was the aim of this investigation. The total counts of bacteria, moulds and yeast were evaluated in the air of technology halls and main and side staircase. The sedimentation Koch’s method was used. The total, number of bacteria of the most investigation points answered to microbial standards of air in food industry, but counts of moulds and yeast were higher than recommended level. Degree of air contamination depended on work activity. The highest contamination of air occurred in areas of winnowing and grinding of roasted cocoa beans, cocoa powder packing machine and ground floor of main staircase.