It is an object of the invention to provide an at of realizing good combustion by lowering a combustion critical temperature below a temperature of intake air sucked into a cylinder, in the case where a first fuel that is difficult to ignite and a second fuel that is easy to ignite are supplied into the cylinder. The invention is a control device for an internal combustion engine that includes a control unit that supplies a first fuel that is difficult to ignite and a second fuel that is easy to ignite into a cylinder, and burns the first fuel that is difficult to ignite as well by igniting the second fuel that is easy to ignite, wherein the control unit carries out at least one of a reduction in a supply amount of the first fuel that is difficult to ignite and an increase in a supply amount of the second fuel that is easy to ignite, if a temperature of intake air sucked into the cylinder falls below a combustion critical temperature.