A burner installable to a boiler for burning a premixed air-fuel mixture, said burner comprising a frame member provided with an elongated combustion head protruding from the frame member and having what in a view from the frame member is its distal end provided with a tip plate, said combustion head comprising an outer, larger diameter tube for a mixture of combustion air and fuel, as well as an inner, smaller diameter tube for combustion air, whereby the combustion head has its outer tube formed with at least one array of aperture lines (31, 37) encircling a body of the outer tube and, in addition, what in a view from the burner's frame member is a distal end opening of the outer tube, i.e. an tip opening at a tip of the outer tube, opens to below the tip plate, said outer tube being configured to be provided with a supply of premixed air-fuel mixture for conveying the premixed air-fuel mixture outward of the combustion head by way of the apertures of at least one array of aperture lines included in the body of the outer tube, as well as by way of the outer tube's tip opening, and the inner tube of the combustion head is continuous and extends from the frame member forward of the tip plate, said tip plate having a width substantially equal to the diameter of the outer tube's tip opening and the direction of a plane defined by the tip plate is transverse to a longitudinal direction of the combustion head, wherein the longitudinal direction of the combustion head is the direction of the longitudinal center axis of the combustion head, characterized in that - between a side edge of the tip plate and the plane of the tip plate is an oblique angle of incidence (a) for directing a gas delivered forward of the tip plate away from the longitudinal center axis of the combustion head, - the combustion head has its tip plate provided with a plurality of air openings extending through the tip plate and it is for cooling the tip plate that the inner tube is additionally provided with a supply of combustion air for conveying the combustion air through the tip plate's air openings. the combustion head has its outer tube formed with at least one array of aperture lines (31, 37) encircling a body of the outer tube and, in addition, what in a view from the burner's frame member is a distal end opening of the outer tube, i.e. an tip opening at a tip of the outer tube, opens to below the tip plate, said outer tube being configured to be provided with a supply of premixed air-fuel mixture for conveying the premixed air-fuel mixture outward of the combustion head by way of the apertures of at least one array of aperture lines included in the body of the outer tube, as well as by way of the outer tube's tip opening, and the inner tube of the combustion head is continuous and extends from the frame member forward of the tip plate, said tip plate having a width substantially equal to the diameter of the outer tube's tip opening and the direction of a plane defined by the tip plate is transverse to a longitudinal direction of the combustion head, wherein the longitudinal direction of the combustion head is the direction of the longitudinal center axis of the combustion head, characterized in that - between a side edge of the tip plate and the plane of the tip plate is an oblique angle of incidence (a) for directing a gas delivered forward of the tip plate away from the longitudinal center axis of the combustion head, - the combustion head has its tip plate provided with a plurality of air openings extending through the tip plate and it is for cooling the tip plate that the inner tube is additionally provided with a supply of combustion air for conveying the combustion air through the tip plate's air openings. - between a side edge of the tip plate and the plane of the tip plate is an oblique angle of incidence (a) for directing a gas delivered forward of the tip plate away from the longitudinal center axis of the combustion head, - the combustion head has its tip plate provided with a plurality of air openings extending through the tip plate and it is for cooling the tip plate that the inner tube is additionally provided with a supply of combustion air for conveying the combustion air through the tip plate's air openings.