Abstract: A method operates a pasteurizing device and a pasteurizing device pasteurizes foodstuff in sealed containers. The pasteurizing device includes a treatment area configured for temperature treatment of the foodstuff in the containers with at least one heating zone, a conveying system for conveying the sealed containers filled with foodstuff through the treatment area and an irrigation device configured for dispensing a temperature-controlled process liquid into the at least one heating zone. The pasteurizing device further includes at least one feed device configured for introducing at least one treatment chemical for container-treatment in gaseous or aerosolized state into the treatment area.