A method of manufacturing a cooling structure which comprises: a first member as a cooling object having a first surface; and a second member arranged above said first surface to have a second surface to oppose to said first surface such that a passage is formed between said first surface and said second surface for a cooling medium to flow, wherein said first member comprises a plurality of prominences which extend upwardly from said first surface, and wherein each of said plurality of prominences extends to be inclined along a direction in which said cooling medium is to flow, and wherein a clearance (b) is formed between a tip of each of said plurality of prominences and said second surface, wherein said method comprises: measuring a first relation of a clearance (b) formed between a tip of each of a plurality of prominences of a first member and a second surface of a second member and a heat transfer rate between a cooling medium and the first member, when said prominences are inclined along a direction in which the cooling medium flows; measuring a second relation of a clearance (b) formed between a tip of each of a plurality of prominences of a first member and a second surface of a second member and a heat transfer rate between a cooling medium and the first member when said prominences extend upwardly from a first surface of the first member; determining as a maximum allowable clearance, a clearance (b) based on said first relation and said second relation such that the heat transfer rate when the prominences are inclined becomes larger than the heat transfer rate when the prominences extend upwardly in a vertical direction; and manufacturing the cooling structure by providing said second member above said first surface such that the actually formed clearance (b) between the tip of each of said plurality of prominences and said second surface is equal to or less than said maximum allowable clearance. a first member as a cooling object having a first surface; and a second member arranged above said first surface to have a second surface to oppose to said first surface such that a passage is formed between said first surface and said second surface for a cooling medium to flow, wherein said first member comprises a plurality of prominences which extend upwardly from said first surface, and wherein each of said plurality of prominences extends to be inclined along a direction in which said cooling medium is to flow, and wherein a clearance (b) is formed between a tip of each of said plurality of prominences and said second surface, wherein said method comprises: measuring a first relation of a clearance (b) formed between a tip of each of a plurality of prominences of a first member and a second surface of a second member and a heat transfer rate between a cooling medium and the first member, when said prominences are inclined along a direction in which the cooling medium flows; measuring a second relation of a clearance (b) formed between a tip of each of a plurality of prominences of a first member and a second surface of a second member and a heat transfer rate between a cooling medium and the first member when said prominences extend upwardly from a first surface of the first member; determining as a maximum allowable clearance, a clearance (b) based on said first relation and said second relation such that the heat transfer rate when the prominences are inclined becomes larger than the heat transfer rate when the prominences extend upwardly in a vertical direction; and manufacturing the cooling structure by providing said second member above said first surface such that the actually formed clearance (b) between the tip of each of said plurality of prominences and said second surface is equal to or less than said maximum allowable clearance. measuring a first relation of a clearance (b) formed between a tip of each of a plurality of prominences of a first member and a second surface of a second member and a heat transfer rate between a cooling medium and the first member, when said prominences are inclined along a direction in which the cooling medium flows; measuring a second relation of a clearance (b) formed between a tip of each of a plurality of prominences of a first member and a second surface of a second member and a heat transfer rate between a cooling medium and the first member when said prominences extend upwardly from a first surface of the first member; determining as a maximum allowable clearance, a clearance (b) based on said first relation and said second relation such that the heat transfer rate when the prominences are inclined becomes larger than the heat transfer rate when the prominences extend upwardly in a vertical direction; and manufacturing the cooling structure by providing said second member above said first surface such that the actually formed clearance (b) between the tip of each of said plurality of prominences and said second surface is equal to or less than said maximum allowable clearance.