The present invention addresses the problem of providing a method for manufacturing a gelatinous food product said method being capable of inhibiting the proliferation of microorganisms in said gelatinous food product during a constant temperature process. The present invention pertains to a method for manufacturing a gelatinous food product said method being characterized by the adjustment of the water activity of a mix during a constant temperature process performed at a temperature lower than a sterilization temperature and higher than a freezing temperature.