The present invention offers an advanced control software verification technology, particularly, an assertion-based verification technology, by providing a control microcomputer verification device and vehicle-mounted control device that exhibit improved verification efficiency. Assertion-based verification is performed with a verification device that has a hardware configuration in which the verification device is independent of a CPU core of a microcomputer but operates in parallel with the CPU core of the microcomputer, which sequentially executes control software. The hardware to be employed to achieve the above purpose is a finite state machine based on microprogrammed control. An interrupt factor is branched immediately before an interrupt controller for the microcomputer and used as a transition input. When an abnormal transition is detected, a warning is output to the microcomputer as an interrupt or output to the outside in the form of a signal.