A submersible electric motor associable with a pump, said submersible electric motor comprising a mainly cylindrical body having a longitudinal axis; an electric motor assembly housed in said mainly cylindrical body; a motor shaft, coaxial with said longitudinal axis, rotatable by said motor assembly and housed at least partially in said mainly cylindrical body; said mainly cylindrical body comprising an outer tubular jacket and a coupling end insertable in said outer tubular jacket; said coupling end being provided with a base wall and a side wall; a device for fixing said motor to said pump; said fixing device comprising at least a first connecting member, insertable in a first hole made in said base wall, and at least a second connecting member insertable in a second hole made in said side wall and in a third hole, made in said outer tubular jacket; said first connecting member being also connectable to a base portion of said pump; characterized in that said first and second holes (210, 220) are communicating, and said first and second connecting members (21, 22) are configured so that the insertion of the first connecting member in the first hole determines the locking of the second connecting member inserted in said second hole and in said third hole, so as to obtain the relative positioning and locking of said outer tubular jacket and said coupling end; said first connecting member having a first threaded portion, adapted to be connected with a respective threaded portion of the first hole; said first connecting member having an end portion, adapted to engage a groove of the second connecting member; said second connecting member being formed by a body comprising a cylindrical intermediate portion having on each side respective cylindrical end portions (231a, 231b), said cylindrical end portions (231a, 231b) having respective diameters (d2a, d2b) greater than the diameter of said cylindrical intermediate portion, so as to form said groove; said second connecting member comprising, laterally with respect to a said cylindrical end portion, a further cylindrical end portion having a diameter greater than the diameter of said cylindrical portions (231a, 231b) and with respect to the diameter of said second hole. a mainly cylindrical body having a longitudinal axis; an electric motor assembly housed in said mainly cylindrical body; a motor shaft, coaxial with said longitudinal axis, rotatable by said motor assembly and housed at least partially in said mainly cylindrical body; said mainly cylindrical body comprising an outer tubular jacket and a coupling end insertable in said outer tubular jacket; said coupling end being provided with a base wall and a side wall; a device for fixing said motor to said pump; said fixing device comprising at least a first connecting member, insertable in a first hole made in said base wall, and at least a second connecting member insertable in a second hole made in said side wall and in a third hole, made in said outer tubular jacket; said first connecting member being also connectable to a base portion of said pump; characterized in that said first and second holes (210, 220) are communicating, and said first and second connecting members (21, 22) are configured so that the insertion of the first connecting member in the first hole determines the locking of the second connecting member inserted in said second hole and in said third hole, so as to obtain the relative positioning and locking of said outer tubular jacket and said coupling end; said first connecting member having a first threaded portion, adapted to be connected with a respective threaded portion of the first hole; said first connecting member having an end portion, adapted to engage a groove of the second connecting member; said second connecting member being formed by a body comprising a cylindrical intermediate portion having on each side respective cylindrical end portions (231a, 231b), said cylindrical end portions (231a, 231b) having respective diameters (d2a, d2b) greater than the diameter of said cylindrical intermediate portion, so as to form said groove; said second connecting member comprising, laterally with respect to a said cylindrical end portion, a further cylindrical end portion having a diameter greater than the diameter of said cylindrical portions (231a, 231b) and with respect to the diameter of said second hole.