To prevent the supply of an unexpected amount of fuel to an engine until learning compensation operation for an accelerator signal ends.

When controlling a fuel injection amount for the diesel engine 10 based on demand injection amount data QD computed by corresponding to the accelerator signal A, a compensation amount for the accelerator signal A is obtained by learning after starting the start operation of the diesel engine 10, demand injection amount data QD is computed by corresponding to a compensation accelerator signal A' obtained by compensating the accelerator signal A in accordance with the compensation amount, and predetermined limit processing is applied to the demand injection amount data QD until the compensation accelerator signal A' after start of the diesel engine 10 is obtained to control a fuel injection amount for the diesel engine 10 based on limit injection amount data LD on which limit processing is applied.