A stringed musical instrument including a body in which a cutaway is formed, wherein the body includes a back board on which at least one brace (14_1-14_4) is provided so as to extend in a width direction of the back board, a longitudinal direction of each of the at least one brace coinciding with the width direction of the back board, wherein a first brace (14_1), which is the closest to the cutaway among the at least one brace (14_1-14_4), has a dimension in the width direction of the back board smaller than a width of the back board at a position of the back board at which the first brace is fixed, the first brace being fixed to the back board such that a distance between a first end (14_1a) of the first brace (14_1) and a first edge portion of the back board is larger than a distance between a second end (14_1b) of the first brace (14_1) and a second edge portion of the back board , two edge portions on an outer periphery of the back board in the width direction at the position of the back board at which the first brace (14_1) is fixed including the first edge portion and the second edge portion that is farther from the cutaway than the first edge portion , the first end (14_1a) of the first brace (14_1) and the second end (14_1b) of the first brace (14_1) being opposite ends of the first brace (14_1), the first end (14_la) of the first brace (14_1) being nearer to the cutaway than the second end (14_lb) of the first brace (14_1) characterized in that the first end (14_1a) of the brace (14_1) is fixed to the back board at a position that is downwardly distant, by a predetermined distance, from a position at which the cutaway is the deepest, the predetermined distance being not smaller than 1 cm, and the first brace (14_1) has a thickness in a direction perpendicular to the back board smaller at its opposite end portions in the width direction than at its central portion in the width direction, and the first brace (14_1) has a shape that is symmetric in the width direction of the back board . wherein the body includes a back board on which at least one brace (14_1-14_4) is provided so as to extend in a width direction of the back board, a longitudinal direction of each of the at least one brace coinciding with the width direction of the back board, wherein a first brace (14_1), which is the closest to the cutaway among the at least one brace (14_1-14_4), has a dimension in the width direction of the back board smaller than a width of the back board at a position of the back board at which the first brace is fixed, the first brace being fixed to the back board such that a distance between a first end (14_1a) of the first brace (14_1) and a first edge portion of the back board is larger than a distance between a second end (14_1b) of the first brace (14_1) and a second edge portion of the back board , two edge portions on an outer periphery of the back board in the width direction at the position of the back board at which the first brace (14_1) is fixed including the first edge portion and the second edge portion that is farther from the cutaway than the first edge portion , the first end (14_1a) of the first brace (14_1) and the second end (14_1b) of the first brace (14_1) being opposite ends of the first brace (14_1), the first end (14_la) of the first brace (14_1) being nearer to the cutaway than the second end (14_lb) of the first brace (14_1) characterized in that the first end (14_1a) of the brace (14_1) is fixed to the back board at a position that is downwardly distant, by a predetermined distance, from a position at which the cutaway is the deepest, the predetermined distance being not smaller than 1 cm, and the first brace (14_1) has a thickness in a direction perpendicular to the back board smaller at its opposite end portions in the width direction than at its central portion in the width direction, and the first brace (14_1) has a shape that is symmetric in the width direction of the back board . <EOS>