The Cronobag is an automatic and secured emptying device of the big bag used in agriculture for granulars and powders. The use of the Cronobag covers others sectors. It is a compact stainless steel device. Three bent blades are protected by a specific belt. The bending of the blades allows the device to be more resistant and permits a diaphragmatic opening of the big bag. They are distributed around a resisting axle, penetrating without being sharp, which stabilizes the balancing of the bag. The security system is set up on springs, preloaded with a 100kg weight, which will open under the burden liberating the blades. Its castellated shape prevents the Big Bag from slipping at the beginning of the emptying and informs the user of the proximity of the blades during manipulations. Some hexagons are cut out in the security system to allow self-cleaning. The Cronobag is a light and simple device to use with the uniqueness of its material which also makes it an esthetically pleasing object. It is multipurpose and resistant, the stainless steel being a token of quality and longevity. It is the first secured emptying system in agriculture which mechanizes dangerous manual operations.