A heat sink includes a pipe through which cooled fluid flows and a cooling block having a first face on which the pipe is placed and a second face to which a heat emitting element is attached. The cooling block has a contact region and a noncontact region at positions where the cooling block faces the pipe. In the contact region, the first face contacts the pipe. In the noncontact region, the first face faces the pipe with a gap therebetween. The contact region is included in a projection region defined by projecting a region of attachment of the heat emitting element onto the first face.