The invention discloses a preservation device. The preservation device comprises a box, a temperature detection device for detecting the temperature of the box, a refrigerating
system for lowering thetemperature in the box, an electrostatic
field device for emitting an electrostatic field to a
food material placing position and a controller for starting the electrostatic
field device and adjusting the refrigerating amount of the refrigerating
system to lower the temperature in the box to a preset temperature range step by step when the box is closed. According to the preservation device, theelectrostatic field can be emitted to the
food material placing position through the electrostatic
field device, transformation of water molecules to a gathered state from a dispersed state can be restrained, and thus the
freezing point of food can be lowered. The controller adjusts the refrigerating amount of the refrigerating
system, the temperature in the box is lowered to the preset temperature range step by step, the temperature in the box is maintained higher than the
freezing point of the food and lower than 0 DEG C and is small in fluctuation,
microbial metabolism can be restrained ata higher degree compared with
common cold storage under the unfreezing condition, the self-
respiratory metabolism rate of the food can be reduced, the nutritional ingredients of the food can be reserved, the edible quality of the food can be improved, and the storage life of the food can be prolonged.