We have carried out high resolution observations with Atacama Large Millimeter/Submillimeter Array ( ALMA ) of continuum emission from Orion KL region .
We identify 11 compact sources at ALMA band 6 ( 245 GHz ) and band 7 ( 339 GHz ) , including Hot Core , Compact Ridge , SMA1 , IRc4 , IRc7 , and a radio source I ( Source I ) .
Spectral energy distribution ( SED ) of each source is determined by using previous 3 mm continuum emission data .
Physical properties such as size , mass , hydrogen number density and column density are discussed based on the dust graybody SED .
Among 11 identified sources , Source I , a massive protostar candidate , is a dominant energy source in Orion KL .
We extensively investigate its SED from centimeter to submillimeter wavelengths .
The SED of Source I can be fitted with a single power-law index of 1.97 suggesting an optically thick emission .
We employ the H ^ { - } free-free emission as an opacity source of this optically thick emission .
The temperature , density , and mass of the circumstellar disk associated with Source I are constrained by the SED of H ^ { - } free-free emission .
Still the fitting result shows a significant deviation from the observed flux densities .
Combined with the thermal dust graybody SED to explain excess emission at higher frequency , a smaller power-law index of 1.60 for the H ^ { - } free-free emission is obtained in the SED fitting .
The power-law index smaller than 2 would suggest a compact source size or a clumpy structure unresolved with the present study .
Future higher resolution observations with ALMA are essential to reveal more detailed spatial structure and physical properties of Source I .