Disclosed is a cooling apparatus for a semiconductor component having a coolant inlet flow path on a coolant flow path connecting a coolant inlet and a coolant outlet, the coolant inlet flow path having a diffuser shape, in which its cross-sectional area increases from a coolant inlet to a portion where cooling fins start to appear. In the cooling apparatus, the coolant inlet flow path meets the following equation: ω=D{3/2+sin(α(x−A))}. Here, ω is the radius of the diffuser, D is the diameter of the coolant inlet, x is a distance from the coolant inlet toward the cooling fins, α is an expansion slope coefficient of the diffuser in radians, and the sine of (α·A) is 1.In the cooling apparatus for a compact and integrated semiconductor component, since the diffuser-shaped coolant inlet flow path extending from the coolant inlet to the cooling fins is designed in an optimal shape, it is possible to improve cooling efficiency and to reduce flow resistance to coolant flow.