A switching vehicle speed determination section (21) judges a traveling mode requested by a driver on the basis of switch position information of a traveling mode switch operated by the driver and determines a switching vehicle speed for switching a hybrid type from a series mode to a parallel mode. A series/parallel modes switching determination section (22) determines switching between the series mode and the parallel mode on the basis of the switching vehicle speed set for the traveling mode determined by the switching vehicle speed determination section (21) and a vehicle speed detected by a vehicle speed sensor. A clutch control section (23) controls engagement/disengagement of a clutch on the basis of a determination result of the series/parallel modes switching determination section (22).