A plate-shaped heat dissipation member comprising a metal-silicon carbide composite containing aluminum or magnesium, wherein the heat dissipation member is substantially rectangular, among two main surfaces (2A, 2B) of the heat dissipation member, one main surface is curved to be convex in an outward direction of the heat dissipation member and the other main surface is curved to be convex in an inward direction of the heat dissipation member, and in a curve C of the other main surface in a cross-sectional view of the heat dissipation member showing a cross-section that is substantially perpendicular to the heat dissipation member and passes both middle points of two short sides of the other main surface, when a straight line passing through both endpoints P 1 and P 2 of the curve C is represented by l 1, a point at which a distance to l 1 on the curve C is maximum is represented by P max, an intersection point between l 1 and a perpendicular drawn from P max to l 1 is represented by P 3, a middle point of a line segment P 1 P 3 is represented by P 4, an intersection point between the curve C and a straight line that passes through P 4 and is perpendicular to l 1 is represented by P mid, and a length of the line segment P 1 P 3 is represented by L, a length of a line segment P 3 P max is represented by H, and a length of a line segment P 4 P mid is represented by h, characterized in that, (2h/L)/(H/L) is 1.1 or more, wherein a value of H/L is 5.0 × 10 -4 or more and 6.0 × 10 -3 or less, and wherein the curvature of a center portion of the other main surface is smaller than that of a portion distant from the center portion of the other main surface. wherein the heat dissipation member is substantially rectangular, among two main surfaces (2A, 2B) of the heat dissipation member, one main surface is curved to be convex in an outward direction of the heat dissipation member and the other main surface is curved to be convex in an inward direction of the heat dissipation member, and in a curve C of the other main surface in a cross-sectional view of the heat dissipation member showing a cross-section that is substantially perpendicular to the heat dissipation member and passes both middle points of two short sides of the other main surface, when a straight line passing through both endpoints P 1 and P 2 of the curve C is represented by l 1, a point at which a distance to l 1 on the curve C is maximum is represented by P max, an intersection point between l 1 and a perpendicular drawn from P max to l 1 is represented by P 3, a middle point of a line segment P 1 P 3 is represented by P 4, an intersection point between the curve C and a straight line that passes through P 4 and is perpendicular to l 1 is represented by P mid, and a length of the line segment P 1 P 3 is represented by L, a length of a line segment P 3 P max is represented by H, and a length of a line segment P 4 P mid is represented by h, characterized in that, (2h/L)/(H/L) is 1.1 or more, wherein a value of H/L is 5.0 × 10 -4 or more and 6.0 × 10 -3 or less, and wherein the curvature of a center portion of the other main surface is smaller than that of a portion distant from the center portion of the other main surface.