We present a multiwavelength study of the cometary \hii region G12.21--0.10 using the VLA and OVRO. Both radio continuum (0.3, 0.7, 2 and 3.6~cm) and spectral lines of H41α, 13CS(2−1) \& (1−0), and NH3(2,2) \& (4,4) observations are included. We find two 3~mm continuum peaks toward G12.21--0.10, one of them is spatially coincident with the UC~H~II region, while the other coincides spatially with a molecular clump. We also find that the 0.7, 2 and 3.6~cm continuum and H41α line are only detected toward the UC~H~II region, while the 13CS, and NH3 is spatially associated with the molecular clump. Based on the morphology, kinetic temperature (∼86~K), volumetric density (∼1.5×106~cm−3) and linear size (∼0.22~pc) of the molecular clump, we suggest this source is consistent with a hot molecular core.
