Provided is lead frame in which a wiring pattern supported by a support piece inside of a one-pitch outer frame section comprises a plurality of base units, each of which comprises a die pad on which a solid-state light emitting element is mounted, a heat sink extending from die pad so as to surround die pad electrically connected to one electrode of the element, and a lead electrically connected to the other electrode of the element. Lead of one base unit among adjacent base units and heat sink of the other base unit are coupled and electrically connected in series. Increase in temperature of the element is inhibited, light output is increased, and cost of a light emitting unit in which a plurality of solid-state light emitting elements connected in series are used is reduced. Also provided are wiring board, light emitting unit, and illuminating apparatus.