To effectively inhibit the deterioration of a catalyst provided in an exhaust path of an internal combustion engine.
A control device of the internal combustion engine (200) has gas fuel supply means (310, 320, 330) supplying gas fuel and liquid fuel supply means (410, 420, 430) supplying liquid fuel, and includes a catalyst temperature detection means (124) detecting a temperature of the catalyst (123) provided in the exhaust path of the internal combustion engine and a fuel ratio determination means (100) determining supply ratios of the gas fuel supplied by the gas fuel supply means and the liquid fuel supplied by the liquid fuel supply means based on the temperature of the catalyst detected by the catalyst temperature detection means, a temperature rising speed of the catalyst, or both the temperature of the catalyst and the temperature rising speed of the catalyst.
NAKAYAMA YUSUKE
Koji Yamamoto
Satoshi Nakamura