An apparatus for producing metal bars and ingots with quality monitoring, includes at least one mold essentially constituted by a body that forms at least one cavity for forming an ingot or a bar and by at least one cover that is detachably associated with the body in order to upwardly close the cavity. The apparatus has at least one passage, provided on the body of the mold, on the cover or on both, for connecting the inside of the cavity to the outside even when the cover is associated with the body in order to upwardly close the cavity. The apparatus according to the invention also has the particularity that it includes a means for taking a sample of the melted material contained in a mold, constituted essentially by a body that forms at least one cavity for forming an ingot or a bar and by at least one cover that is detachably associated with the body in order to upwardly close the cavity. The present invention also relates to a plant and a method for producing metal bars and ingots with quality monitoring.