Leakage diagnosis device and leakage diagnosis method

A leakage diagnosis device that carries out a leakage diagnosis on the basis of an internal pressure state of an airtight compartment by emitting gas from the compartment via a canister during a stop of an internal combustion engine, the compartment being formed in an evaporative fuel processing mechanism for the internal combustion engine, the evaporative fuel processing mechanism including a fuel tank, and the leakage diagnosis device comprising:

• a detecting unit that detects a physical quantity that reflects a fuel adsorption state of the canister;
• and
• a leakage diagnosis repeating unit that repeats the leakage diagnosis within the number of times of the leakage diagnosis, limited on the basis of the detected physical quantity.