A highly accurate control is achieved in such a way that a timing value is generated from a differential control amount calculation result and a filter calculation result at iteration intervals not exceeding the iteration intervals of the filter calculation and then the timing set value of a driving signal generation circuit is updated by this timing value. A device for controlling a power conversion circuit comprises an AD conversion circuit (22), a driving timing value generation circuit (23), and a driving signal generation circuit (24). The driving timing value generation circuit (23) includes a control amount calculation circuit (231) and a digital-digital addition circuit (232). The digital-digital addition circuit (232) generates a driving timing value for a switch of a power conversion circuit. The driving signal generation circuit (24) receives the driving timing value and generates a driving signal for the switch (11) of the power conversion circuit (1).