Apparatus to fully automatically open the side and reclined walls of a plurality of crates preferably for agricultural products, provided with a bottom plane and with two pairs of opposed walls (3, 3A-4, 4A), each of them hinged on said bottom plane, which are arranged in the same and ordered way, and vertically laid one on the other so as to form a respective first stack, said apparatus comprising: a) means for carrying said first stack into a first loading station (S-1), b) first means for vertically raising two opposed walls of the upper crate by respective rotation with respect to said bottom plane, c) second means for vertically rising the other two opposed walls (4, 4A) of the upper crate by respective rotation with respect to said bottom plane, d) means for blocking (205, 205A) at least one of said side walls to an adjacent side wall, e) means for horizontally transferring said open crate into a position outside the vertical projection of said first stack, f) means for lifting (47, 47A, 48, 48A) said first stack such that the crate in the upper position and with the reclined side walls reaches a pre-determined level into said first loading station (S-1) after said first stack is carried into said first loading station (S-1), g) means for lowering (57, 57A, 58, 58A) said crate until a support level of the respective bottom plane on a second working station (S-2) able of forming a train of open crates, wherein said means for blocking at least one of said side walls to an adjacent side wall and for horizontally transferring said open crate into a position outside the vertical projection of said first stack are operated through the use of a centre operating body able of: - being initially lowered until it is introduced into an opened crate, - being acted so as to increase one horizontal size and to contact the side edges of two opposed walls, and to engage by pushing said two edges to corresponding edges of the other two walls, - keeping on engaged by pushing said crate and to be horizontally transferred, possibly after a lifting motion, so as to automatically transfer said crate, - being able to be lowered for strokes (C1, C2), which can be selectively differentiated, with respect to a common initial level, characterized in that said first station (S-1) is able of lifting, one by one, a train of stacks of closed crates, and comprising: - two supporting frames (470, 480) which are parallel and horizontally extended, each provided with a couple of respective lifting mountings (47, 47A, --- 48, 48A) able of supporting a respective stack of closed crates, - working devices able of impressing to said supporting frames a shifting train which includes: ▪ increasing of the reciprocal horizontal distance from a first distance to a second distance, ▪ synchronous lowering of said supporting frames (470, 480), ▪ re-approaching of said supporting frames (470, 480) to the starting distance, ▪ incidental final lifting of same said supporting frames (470, 480) for a predefined amount. a) means for carrying said first stack into a first loading station (S-1), b) first means for vertically raising two opposed walls of the upper crate by respective rotation with respect to said bottom plane, c) second means for vertically rising the other two opposed walls (4, 4A) of the upper crate by respective rotation with respect to said bottom plane, d) means for blocking (205, 205A) at least one of said side walls to an adjacent side wall, e) means for horizontally transferring said open crate into a position outside the vertical projection of said first stack, f) means for lifting (47, 47A, 48, 48A) said first stack such that the crate in the upper position and with the reclined side walls reaches a pre-determined level into said first loading station (S-1) after said first stack is carried into said first loading station (S-1), g) means for lowering (57, 57A, 58, 58A) said crate until a support level of the respective bottom plane on a second working station (S-2) able of forming a train of open crates, - being initially lowered until it is introduced into an opened crate, - being acted so as to increase one horizontal size and to contact the side edges of two opposed walls, and to engage by pushing said two edges to corresponding edges of the other two walls, - keeping on engaged by pushing said crate and to be horizontally transferred, possibly after a lifting motion, so as to automatically transfer said crate, - being able to be lowered for strokes (C1, C2), which can be selectively differentiated, with respect to a common initial level, - two supporting frames (470, 480) which are parallel and horizontally extended, each provided with a couple of respective lifting mountings (47, 47A, --- 48, 48A) able of supporting a respective stack of closed crates, - working devices able of impressing to said supporting frames a shifting train which includes: ▪ increasing of the reciprocal horizontal distance from a first distance to a second distance, ▪ synchronous lowering of said supporting frames (470, 480), ▪ re-approaching of said supporting frames (470, 480) to the starting distance, ▪ incidental final lifting of same said supporting frames (470, 480) for a predefined amount. ▪ increasing of the reciprocal horizontal distance from a first distance to a second distance, ▪ synchronous lowering of said supporting frames (470, 480), ▪ re-approaching of said supporting frames (470, 480) to the starting distance, ▪ incidental final lifting of same said supporting frames (470, 480) for a predefined amount.