A submerged combustion melter comprising a melting chamber having a periphery, a base, a vertical central melting chamber axis and a burner positioning plane, the melter being equipped with: a raw material feeder; a melt outlet; and at least five submerged combustion burners (21, 22, 23, 24, 25), each of the at least five submerged combustion burners (21, 22, 23, 24, 25) having a respective central burner axis (31, 32, 33, 34, 35) and one or more nozzle outlets (41,42,43,44,45); the burner positioning plane being perpendicular to the central melter axis and arranged at a weighted average distance with respect to each of the nozzle outlets (41,42,43,44,45); each of the at least five submerged combustion burners (21, 22, 23, 24, 25) is arranged to project from a respective burner position (51,52,53,54,55) defined by the intersection between the projection of its central burner axis (31, 32, 33, 34, 35) and the positioning plane; characterized in that each burner position (51,52,53,54,55) is arranged at a respective adjacent burner spacing (512,523,534,545,551) with respect to each of its two closest adjacent burner positions (51,52,53,54,55) and the difference between each adjacent burner spacing and the mean average of the adjacent burner spacings is less than or equal to 20% of the mean average of the adjacent burner spacings; each central burner axis (31, 32, 33, 34, 35) has a respective burner axis circle (71,72,73,74,75) which projects around the central burner axis (31, 32, 33, 34, 35) and has a radius (r1,r2,r3,r4,r5) which is equal to its weighted burner axis - periphery distance in the melter, that is in cases where the burner axis and the peripheral wall(s) of the melting chamber are parallel the distance between the burner axis and the peripheral wall, and in other cases the arithmetic mean distance over the height of the melting chamber between the burner axis and its closest portion of peripheral wall; the difference between the radius of each burner-axis circle (71,72,73,74,75) and the mean average radius of the burner-axis circles (71,72,73,74,75) is less than or equal to 20% of the mean average radius of burner-axis circles; and the melter has a central zone at the positioning plane defined between the burner axis circles (71,72,73,74,75) at the positioning plane, the central melting zone having a diameter of at least 250 mm. a raw material feeder; a melt outlet; and at least five submerged combustion burners (21, 22, 23, 24, 25), each of the at least five submerged combustion burners (21, 22, 23, 24, 25) having a respective central burner axis (31, 32, 33, 34, 35) and one or more nozzle outlets (41,42,43,44,45); the burner positioning plane being perpendicular to the central melter axis and arranged at a weighted average distance with respect to each of the nozzle outlets (41,42,43,44,45); each of the at least five submerged combustion burners (21, 22, 23, 24, 25) is arranged to project from a respective burner position (51,52,53,54,55) defined by the intersection between the projection of its central burner axis (31, 32, 33, 34, 35) and the positioning plane; characterized in that each burner position (51,52,53,54,55) is arranged at a respective adjacent burner spacing (512,523,534,545,551) with respect to each of its two closest adjacent burner positions (51,52,53,54,55) and the difference between each adjacent burner spacing and the mean average of the adjacent burner spacings is less than or equal to 20% of the mean average of the adjacent burner spacings; each central burner axis (31, 32, 33, 34, 35) has a respective burner axis circle (71,72,73,74,75) which projects around the central burner axis (31, 32, 33, 34, 35) and has a radius (r1,r2,r3,r4,r5) which is equal to its weighted burner axis - periphery distance in the melter, that is in cases where the burner axis and the peripheral wall(s) of the melting chamber are parallel the distance between the burner axis and the peripheral wall, and in other cases the arithmetic mean distance over the height of the melting chamber between the burner axis and its closest portion of peripheral wall; the difference between the radius of each burner-axis circle (71,72,73,74,75) and the mean average radius of the burner-axis circles (71,72,73,74,75) is less than or equal to 20% of the mean average radius of burner-axis circles; and the melter has a central zone at the positioning plane defined between the burner axis circles (71,72,73,74,75) at the positioning plane, the central melting zone having a diameter of at least 250 mm.