A plate (3) having a pair of first communication holes (34) and a pair of second communication holes (35) and a plate (4) having a pair of first communication holes (44) and a pair of second communication holes (45) are alternately laminated to alternately form, between the plates (3) and (4) adjacent to each other, a first coolant flow path (81) and a second coolant flow path (82); a first spacer (5) is interposed around each of the first communication holes (34) and (44) within the first coolant flow path (81); and a second spacer (6) is interposed within the second coolant flow path (82) and at a position corresponding to a periphery of each of the first communication holes (34) and (44).