To remarkably reduce the soot to be generated when burning with heating of a combustion chamber casing, and to remarkably reduce precipitates generated in a range of a combustion chamber, and to shorten a starting process by heating a combustion chamber forming group.

This combustion forming group 12 for a heater for a vehicle is provided with the combustion chamber casing, and the combustion chamber 16 is limited by the outer wall 14 of the combustion chamber inside of the combustion casing. The combustion chamber 16 has a combustion chamber outlet opening 24 for discharging the exhaust gas generated by combustion to a smoke tube 26, and the combustion chamber 16 is also provided with a direction changing device for changing direction of at least one partial flow of the exhaust gas flowing from the combustion chamber 16 to flow along at least one partial range of the outside 44 positioning in a side of the combustion chamber outer wall opposite to the combustion chamber 16.