Disclosed is a food sterilization method capable of heat-sterilizing foods uniformly by heating steam irrespectively with a shape of an apparatus. The food sterilization method includes introducing the food into the inside of the heat-sterilizing chamber through the opening of the opening and closing part discharging the air in the inside of the heat-sterilizing chamber through the air discharging part, close contacting the sealing cover and the heat-sterilizing chamber by absorption force of the air to seal the inside of the heat-sterilizing chamber, and then reducing a pressure in the inside of the heat-sterilizing chamber closing the air discharging part, supplying the steam from the steam supplying part to the inside of the heat-sterilizing chamber to close contact the sealing cover and the opening of the opening and closing part by a pressure of the steam and thereby seal the opening and closing part and the inside of the heat-sterilizing chamber, and then heat-sterilizing the food introduced into the inside of the heat-sterilizing chamber by the steam supplied from the steam supplying part and at the same time, discharging some of the steam in the inside of the heat-sterilizing chamber through the steam discharging part during the heat-sterilization closing the steam supplying part, and discharging the steam in the inside of the heat-sterilizing chamber through the steam discharging part and taking the food out of the heat-sterilizing chamber through the opening of the opening and closing part.
