To realize an A/D conversion controller capable of performing A/D conversion during a period when fluctuations do not occur by monitoring timing when load fluctuations occur in a device having such a load that irregularly generates large fluctuations.

This A/D conversion controller is provided with a load controlling means for controlling the load that irregularly generates fluctuations and an A/D conversion controlling means for controlling an A/D conversion circuit for sampling continuous input signals, and gives fluctuation information from the load controlling means to the A/D conversion controlling means.