To provide a structure that provides a rigidity that is high enough to withstand vibrations of an exhaust pipe of an internal combustion engine, in an exhaust gas control apparatus arranged in the exhaust pipe.

Cooling fins 40 are fixed to both a holder portion 36 and a flange 38. Thus, the cooling fins 40 serve not only a cooling (heat dissipating) function but also a function as reinforcing ribs. Therefore, the cooling fins 40 increase the rigidity of an injection valve holder 32, thereby making it possible to suppress occurrence of an offset of the direction of a spray formed by a urea solution injection valve 16 from the proper direction due to the deflection of the urea solution injection valve 16 and insufficient sealing performance between flanges 38, 42.