Abstract: To provide a novel organometallic complex and a novel light-emitting device that are useful or reliable. The organometallic complex includes platinum (Pt), a cyano group, and a phenyl group that has two alkyl groups at the ortho-positions. The light-emitting device includes an organic compound layer held between a pair of electrodes; the organic compound layer includes a light-emitting layer; the light-emitting layer contains an organic compound and the organometallic complex; the organometallic complex includes platinum (Pt), a cyano group, and a phenyl group that has two alkyl groups at the ortho-positions; and the difference between the LUMO level of the organic compound and the HOMO level of the organometallic complex is greater than or equal to 2.5 eV and less than or equal to 3.0 eV.

Abstract: A metal part is uniformly cooled by uniformly breaking a vapor film formed when a cooling liquid vaporizes on a surface of the metal part. Oscillations are applied to the vapor film formed on the surface of the metal part, whereby the vapor film is broken without the stirring of a cooling liquid 1. The cooling liquid 1 is stirred after the vapor film begins to be broken, whereby bubbles formed by the breakage of the vapor film are caused to diffuse in the cooling liquid 1.