Vehicle control device

A vehicle control device (100) is mounted in a vehicle (1) provided with an engine (10) capable of using a first fuel and a second fuel the emission of which is worse than that of the first fuel, a fuel switching means (21, 23, 31) capable of supplying the first fuel and the second fuel to the engine while performing switching between the first fuel and the second fuel, and a catalyst (13) disposed in an exhaust system (12) of the engine, said vehicle control device being provided with a catalyst deterioration detection means (31) capable of detecting deterioration of the catalyst, and a control means (31) for controlling the catalyst deterioration detection means such that the deterioration is detected when the operation area of the vehicle corresponds to an operation area suitable for the deterioration detection and the first fuel is supplied to the engine by the fuel switching means.