A cold plate includes: a base plate including a plurality of fins aligned in parallel; and a cover that covers the plurality of fins and that forms an internal space between the base plate and the cover. The plurality of fins includes: a first fin group in which a plurality of first fins having a first width are disposed on the base plate with a fixed gap in a parallel direction between each of the first fins and a second fin group in which a plurality of second fins having a width wider than the first width are disposed on the base plate with the fixed gap in the parallel direction between each of the second fins. The second fin group is disposed on both sides of the first fin group.