Provided is a novel substance that can emit phosphorescence. Alternatively, provided is a novel substance with high emission efficiency. An organometallic complex in which a 4-arylpyrimidine derivative is a ligand and iridium is a central metal is provided. Specifically, an organometallic complex having a structure represented by a general formula (G1) is provided. In the general formula (G1), R1 represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, R2 represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and a substituted or unsubstituted phenyl group, R3 represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and Ar1 represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms.