A voltage measurement device includes a voltage measurement circuit part, a voltage generation circuit part, and a control unit. In a voltage measurement mode, a measurement result of the input voltage is detected as an output voltage value based on the output signal of the voltage measurement circuit part. In a self-diagnosis mode, it is determined whether the measured output voltage value when the lower limit voltage is applied by the voltage generation circuit part is within a specific lower limit range (first determination). Further, a specific intermediate range is set based on the output voltage value and a specific upper limit range, and it is determined whether the output voltage value when the intermediate voltage is applied by the voltage generation circuit part is within the specific intermediate range (second determination). Self-diagnosis of the voltage measurement circuit part is performed based on the first and second determinations.