Operation input device

An operation input device comprising:

• a detection unit configured to sense a detection value changing according to a distance to a detection target object;
• and
• a controller configured to detect input operation in a case where the detection value is equal to or greater than a first threshold indicating that a distance between the detection target object and the detection unit is equal to or shorter than a first distance, wherein
• the controller stands by in a sleep mode in which a power consumption is reduced as compared to a normal standby mode in a case where the detection value is less than a second threshold, which is smaller than the first threshold, as a threshold indicating that the distance between the detection target object and the detection unit is equal to or shorter than a second distance longer than the first distance, and stands by in the normal standby mode in a case where the detection value is equal to or greater than the second threshold.