A machining center comprising: - two workpiece-supporting tables (T1, T2), - two first guides (G1, G2), which extend parallel to a first direction; each table (T1, T2) being movable along a respective of said first guides (G1, G2), - two second guides (W1, W2), which extend parallel to a second direction transverse to said first direction, - two machining assemblies (K1, K2), a first machining assembly comprising at least one machining head (H1, H1bis), and a second assembly comprising at least one machining head; each machining assembly (K1, K2) being movable parallel to said second direction along a respective of said second guides (W1, W2); - a portal structure arranged transversely to said first guides (G1, G2); on at least one side (12, 13) of said portal structure one said machining assembly being movable parallel to said second direction, on a respective second guide, said portal structure being superimposed on an intermediate position of said first guides (G1, G2), so that said tables (T1, T2) are movable on said first guides (G1, G2) under said portal structure, passing from one side to the other (12, 13) of said portal structure, - a load-bearing structure provided in second end areas of said first guides (G1, G2), on the opposite side with respect to first end areas, at least one said second guide for said first machining assembly being provided on said load-bearing structure, - four machining areas (J11, J12, J21, J22) in which the two machining assemblies (K1, K2) can operate on workpieces present on said tables (T1, T2); along each first guide (G1, G2), that is for a respective table (T1, T2), two machining areas being present, one for each machining assembly (K1, K2), so that each machining assembly (K1, K2) can operate, according to a programmed machining cycle, on both workpiece-supporting tables (T1, T2), - two workpiece loading/unloading areas (F10, F20) defined in said first end areas, one for each workpiece-supporting table (T1, T2), - an electronic control unit on which a program for managing the cycle of movements of said tables (T1, T2) is provided; - two workpiece-supporting tables (T1, T2), - two first guides (G1, G2), which extend parallel to a first direction; each table (T1, T2) being movable along a respective of said first guides (G1, G2), - two second guides (W1, W2), which extend parallel to a second direction transverse to said first direction, - two machining assemblies (K1, K2), a first machining assembly comprising at least one machining head (H1, H1bis), and a second assembly comprising at least one machining head; each machining assembly (K1, K2) being movable parallel to said second direction along a respective of said second guides (W1, W2); - a portal structure arranged transversely to said first guides (G1, G2); on at least one side (12, 13) of said portal structure one said machining assembly being movable parallel to said second direction, on a respective second guide, said portal structure being superimposed on an intermediate position of said first guides (G1, G2), so that said tables (T1, T2) are movable on said first guides (G1, G2) under said portal structure, passing from one side to the other (12, 13) of said portal structure, - a load-bearing structure provided in second end areas of said first guides (G1, G2), on the opposite side with respect to first end areas, at least one said second guide for said first machining assembly being provided on said load-bearing structure, - four machining areas (J11, J12, J21, J22) in which the two machining assemblies (K1, K2) can operate on workpieces present on said tables (T1, T2); along each first guide (G1, G2), that is for a respective table (T1, T2), two machining areas being present, one for each machining assembly (K1, K2), so that each machining assembly (K1, K2) can operate, according to a programmed machining cycle, on both workpiece-supporting tables (T1, T2), - two workpiece loading/unloading areas (F10, F20) defined in said first end areas, one for each workpiece-supporting table (T1, T2), - an electronic control unit on which a program for managing the cycle of movements of said tables (T1, T2) is provided;