The authors reported on investigation of the thermal conductivity of graphene suspended across trenches in $\mathrm{Si}∕\mathrm{Si}{\mathrm{O}}_2$ wafer. The measurements were performed using a noncontact technique based on micro-Raman spectroscopy. The amount of power dissipated in graphene and corresponding temperature rise were determined from the spectral position and integrated intensity of graphene’s $G$ mode. The extremely high thermal conductivity in the range of $\sim 3080–5150\mathrm{W}∕\mathrm{m}\mathrm{K}$ and phonon mean free path of $\sim 775\mathrm{nm}$ near room temperature were extracted for a set of graphene flakes. The obtained results suggest graphene’s applications as thermal management material in future nanoelectronic circuits.