The　temperature　variation　of　the　testing　sample　can　result　in　the　density　change　of　the　surrounding　air,　and　then　the　refractive　index　of　the　air　is　altered　accordingly.　Therefore,　the　temperature　can　be　obtained　by　detecting　the　phase.　In　this　contribution,　the　digital　holography　is　presented　to　measure　the　temperature　distribution,　which　can　achieve　the　full-field　and　non-destructive　detection.　The　phase　distribution　can　be　determined　by　applying　a　single　fast　Fourier　transform　to　the　digital　hologram.　In　the　experiment,　the　LFT　digital　holography　system　is　built　and　employed　to　inspect　the　temperature　field　of　an　electric　soldering　iron.　The　phase　images　are　obtained,　showing　the　temperature　distributions　around　the　iron　with　different　position　and　time.　The　experimental　results　demonstrate　the　feasibility　and　effectiveness　of　the　digital　holography　for　the　temperature　measurement.