COOLER

To make it possible to stably cool a heat-generating element while reducing pressure loss in at least one of an inlet portion of a refrigerant into a diversion flow path and the outlet portion of the refrigerant from the diversion flow path compared to a conventional technology.SOLUTION: A cooler 100 includes a first flow path FP1 of a first width through which a refrigerant flows along a first axis, a second flow path FP3 of a second width through which a refrigerant flows along the first axis, a first portion having a first surface on which a plurality of branch flow paths FP3 along a second axis intersecting the first axis are arranged in the direction of the first axis, and a second surface opposite the first surface and performing heat exchange with a body to be cooled, and the first flow path FP1 has a first opening OPb1 facing the first surface, and the second flow path FP2 has a second opening OPb2 facing the first surface, and at least one of the pair of the width and first width of the first opening OPb1 in the direction of the second axis and the pair of the width and second width of the second opening OPb2 in the direction of the second axis are equal to each other.SELECTED DRAWING: Figure 5 【課題】分流流路への冷媒の流入部、及び、分流流路からの冷媒の流出部のうち、少なくとも一方における圧力損失を、従来技術に比較して低減しながら、発熱体を安定的に冷却することを可能とする。【解決手段】冷却器１００は、第１軸に沿って冷媒が流通する第１幅の第１流路ＦＰ１と、第１軸に沿って冷媒が流通する第２幅の第２流路ＦＰ３と、第１軸に交差する第２軸に沿う複数の分流流路ＦＰ３が第１軸の方向に配列された第１面と、第１面の反対側の面であって被冷却体と熱交換する第２面とを含む第１部分とを備え、第１流路ＦＰ１は、第１面に対向する第１開口ＯＰｂ１を有し、第２流路ＦＰ２は、第１面に対向する第２開口ＯＰｂ２を有し、第２軸の方向における第１開口ＯＰｂ１の幅と第１幅との組、及び、第２軸の方向における第２開口ＯＰｂ２の幅と第２幅との組のうちの少なくとも一方は、互いに等しい。【選択図】図５