A cooler with a cooler main body that, in one configuration, includes a first wall portion forming a cooling surface that cools an electronic component, a second wall portion disposed opposing the first wall portion, and a side wall portion that connects a periphery of the first wall portion and a periphery of the second wall portion. In the configuration, cooling fins are attached to an inner wall surface of the first wall portion, a refrigerant introduction pipe and refrigerant introduction flow path for supplying refrigerant to the cooling fins and a refrigerant discharge pipe and refrigerant discharge flow path for ejecting refrigerant from the cooling fins are included, and protruding portions and are provided on the first wall portion side of the refrigerant introduction flow path.