A heat sink includes a graphite plate, two base materials each of which is disposed adjacent to the graphite plate, and a fixing member, in which the graphite plate has a strip shape and includes a fin portion and a base portion provided at one end of the fin portion, the base material includes a hole into which the fixing member can be inserted, the fixing member is inserted into the holes of the two base materials so that the two base materials are disposed to be adjacent to both sides of the base portion in a thickness direction, the base portion is in close contact with the base material adjacent to each other on both sides of the base portion in the thickness direction, the adjacent base materials are crimped and fixed by the fixing member in a state of being in close contact with each other, and in a case where a surface roughness of the fin portion is defined as Ra1, a surface roughness of the base material is defined as Ra2, and a surface roughness of the base portion is defined as Ra3, a relationship of Ra1>Ra2≥Ra3 is satisfied.