Information processing device and vehicle

An information processing device includes an acquisition unit which acquires use history information indicating a use history of the vehicle for a plurality of items, a derivation unit which derives an output decrease amount for each of the items based on the use history information and output decrease characteristic information, a factor-specific output decrease amount estimation unit which estimates the output decrease amount for each output decrease factor based on the output decrease amount for each item and output decrease factor information, and a control unit. When an output decrease amount for a predetermined output decrease factor is equal to or larger than a threshold value, the control unit executes adhering substance removal control of supplying a nitrogen-enriched gas having a higher nitrogen concentration and a lower oxygen concentration than air to the fuel cell as a cathode gas.