To stabilize battery voltage without big electricity carry to a electric heating catalyst more than necessary even at a time of cold engine condition or the like and to improve ignitability without especially increasing the number of parts to make an air fuel-ratio lean and to make catalyst function fully demonstrated.

A heater 11b of the electric heating catalyst 11, a power steering device 13, an ignition coil 14 are connected to a high voltage system, and ECU 50 is connected to a low voltage system. The heater 11b of the electric heating catalyst 11 is energized at the time of cold engine condition. Ignition control of the ECU 50 is realized by repeating energization/deenergization of a primary coil 14a by turning on/off a power transistor 16a to realize multiple electric discharge by repeating plural times of discharging during one combustion cycle. Consequently, multiple ignition is performed to make air-fuel ratio lean at the time of cold engine condition energizing the heater 11b of the electric heating catalyst 11.