A process for controlling the flows of liquid metal in a continuous casting of thin slabs, wherein there are provided: - a crystallizer comprising perimetral walls (16, 16', 17, 18) which define a containment volume for a liquid metal bath; - a discharger centrally arranged in said bath to discharge said liquid metal; - a first electromagnetic brake for generating a first braking zone in a central portion of said bath in proximity of an outlet section of said liquid metal from said discharger, said central portion being delimited between two perimetral front walls (16,16') of said crystallizer; - a second electromagnetic brake for generating a second braking zone in said central portion of said bath in a position underneath said first braking zone; - a third electromagnetic brake for generating a third braking zone in a first side portion of said bath between said central portion and a first perimetral sidewall substantial orthogonal to said front walls (16,16'); - a fourth electromagnetic brake for generating a fourth braking zone within a second side portion of said bath, which is symmetric to said first side portion of said bath with respect to a symmetry plane (A-A) substantially orthogonal to said front perimetral walls (16,16'); - a fifth electromagnetic brake for generating a fifth braking zone mainly in said first side portion of said bath in a position mainly underneath said third braking zone; - a sixth electromagnetic brake for generating a sixth braking zone in said second side portion of said bath in a position mainly underneath said fourth braking zone, each of said electromagnetic brakes (10', 11', 12', 13', 14', 15') comprising a pair of magnetic poles symmetrically arranged with respect to a symmetry plane (B-B) of said crystallizer, which is substantially parallel to opposite front walls (16, 16') of said crystallizer, each magnetic pole comprising a core and a coil supplied by direct current, said magnetic poles (10', 11', 12', 13', 14', 15') being configured so as to generate a magnetic field which crosses said bath according to directions substantially orthogonal to said front walls (16,16') of said crystallizer, said apparatus comprising a pair of reinforcing walls (20, 20'), each externally adjacent to one of said front walls (16, 16') of said crystallizer, said apparatus comprising a pair of ferromagnetic plates (21, 21') each arranged parallel to one of said reinforcing walls (20, 20') so that the magnetic poles, arranged on a same side with respect to said symmetry plane (B-B), are comprised between one of said reinforcing walls (20, 20') and one of said ferromagnetic plates (21, 21'), - wherein said process includes activating said braking zones (10, 11, 12, 13, 14, 15) either independently or in groups according to characteristic parameters of the fluid-dynamic conditions of said liquid metal in said bath. - a crystallizer comprising perimetral walls (16, 16', 17, 18) which define a containment volume for a liquid metal bath; - a discharger centrally arranged in said bath to discharge said liquid metal; - a first electromagnetic brake for generating a first braking zone in a central portion of said bath in proximity of an outlet section of said liquid metal from said discharger, said central portion being delimited between two perimetral front walls (16,16') of said crystallizer; - a second electromagnetic brake for generating a second braking zone in said central portion of said bath in a position underneath said first braking zone; - a third electromagnetic brake for generating a third braking zone in a first side portion of said bath between said central portion and a first perimetral sidewall substantial orthogonal to said front walls (16,16'); - a fourth electromagnetic brake for generating a fourth braking zone within a second side portion of said bath, which is symmetric to said first side portion of said bath with respect to a symmetry plane (A-A) substantially orthogonal to said front perimetral walls (16,16'); - a fifth electromagnetic brake for generating a fifth braking zone mainly in said first side portion of said bath in a position mainly underneath said third braking zone; - a sixth electromagnetic brake for generating a sixth braking zone in said second side portion of said bath in a position mainly underneath said fourth braking zone, each of said electromagnetic brakes (10', 11', 12', 13', 14', 15') comprising a pair of magnetic poles symmetrically arranged with respect to a symmetry plane (B-B) of said crystallizer, which is substantially parallel to opposite front walls (16, 16') of said crystallizer, each magnetic pole comprising a core and a coil supplied by direct current, said magnetic poles (10', 11', 12', 13', 14', 15') being configured so as to generate a magnetic field which crosses said bath according to directions substantially orthogonal to said front walls (16,16') of said crystallizer, said apparatus comprising a pair of reinforcing walls (20, 20'), each externally adjacent to one of said front walls (16, 16') of said crystallizer, said apparatus comprising a pair of ferromagnetic plates (21, 21') each arranged parallel to one of said reinforcing walls (20, 20') so that the magnetic poles, arranged on a same side with respect to said symmetry plane (B-B), are comprised between one of said reinforcing walls (20, 20') and one of said ferromagnetic plates (21, 21'), - wherein said process includes activating said braking zones (10, 11, 12, 13, 14, 15) either independently or in groups according to characteristic parameters of the fluid-dynamic conditions of said liquid metal in said bath.