A cooling promoting structure for a gas turbine component which is provided in a cooling flow path which is formed between a first member and a second member disposed to face each other, comprising: a plurality of first flow path walls which are erected on the first member at equal intervals in a front-rear direction of the first member and form first flow paths on the first member side of the cooling flow path (Ice); and a plurality of second flow path walls which are erected on the second member at equal intervals in a front-rear direction of the second member and form second flow paths on the second member side of the cooling flow path (Ice), and characterised in that each of the first flow path walls includes a first collision surface which collides with cooling gas flowing through the first flow path at locations where the first flow path is bent and at which the cooling air flows from the first flow path into the second flow path, and each of the second flow path walls includes a second collision surface which collides with cooling gas flowing through the second flow path at locations where the second flow path is bent and at which the cooling air flows from the second flow path into the first flow path, the distance in the thickness direction of the first flow path wall of the first collision surface from the first member is set so as to be the same as the distance in the thickness direction of the second flow path wall of the second collision surface from the second member such that a boundary surface between the first flow path wall and the second flow path wall becomes a flat surface except for the connection location between the first flow path and the second flow path, each of the first flow path walls is formed in a wave form in which bending is repeated at a constant period, each of the second flow path walls is formed in a wave form in which bending is repeated at the same constant period of the wave form formed by the first flow path walls, and a phase of the wave form formed by the second flow path walls is shifted 180° to a phase of the wave form formed by the first flow path wall. a plurality of first flow path walls which are erected on the first member at equal intervals in a front-rear direction of the first member and form first flow paths on the first member side of the cooling flow path (Ice); and a plurality of second flow path walls which are erected on the second member at equal intervals in a front-rear direction of the second member and form second flow paths on the second member side of the cooling flow path (Ice), and characterised in that each of the first flow path walls includes a first collision surface which collides with cooling gas flowing through the first flow path at locations where the first flow path is bent and at which the cooling air flows from the first flow path into the second flow path, and each of the second flow path walls includes a second collision surface which collides with cooling gas flowing through the second flow path at locations where the second flow path is bent and at which the cooling air flows from the second flow path into the first flow path, the distance in the thickness direction of the first flow path wall of the first collision surface from the first member is set so as to be the same as the distance in the thickness direction of the second flow path wall of the second collision surface from the second member such that a boundary surface between the first flow path wall and the second flow path wall becomes a flat surface except for the connection location between the first flow path and the second flow path, each of the first flow path walls is formed in a wave form in which bending is repeated at a constant period, each of the second flow path walls is formed in a wave form in which bending is repeated at the same constant period of the wave form formed by the first flow path walls, and a phase of the wave form formed by the second flow path walls is shifted 180° to a phase of the wave form formed by the first flow path wall.