Provided is a dispersant including a hydrophobic moiety with a branched alkyl group and an arylene group and a hydrophilic moiety with an alkylene oxide group and a carboxylic acid group. The alkyl group is a substituted or unsubstituted alkyl group of 5-30 carbon atoms, the arylene group is a substituted or unsubstituted arylene group of 6-30 carbon atoms, and the alkylene oxide group is a substituted or unsubstituted alkylene oxide group of 2-10 carbon atoms. The dispersant has good dispersibility, and a low residual carbon content after sintering. Thus, a paste composition including the dispersant can maintain a low viscosity and disperse many inorganic particles. Thus, an inorganic device prepared using the paste composition can have a low residual carbon content and a high packing density.