The invention provides a mini environment apparatus, an inspection apparatus, a manufacturing apparatus and a cleaning method of a space which can suppress an influence of a cleanliness of an external environment and can keep a target cleanliness of a specific space. The invention is provided with an outer dust collecting filter 3a for covering an intake port 2b of a casing 2, an outer fan 3b for flowing an air from an external environment into the casing 2 via the outer dust collecting filter 3a, a clean chamber 4a arranged within the casing 2 and having an intake port 4b facing to a space within the casing 2, an inner dust collecting filter 5a for covering the intake port 4b, an inner fan 5b for flowing the air within the casing 2 into the clean chamber 4a via the inner dust collecting filter 5a, a pressure gauge 6a measuring a pressure in an external environment of the casing 2, a pressure gauge 6b measuring a pressure within the casing 2, a pressure gauge 6c measuring a pressure within the clean chamber 4a, and a control unit 7 for controlling rotating speeds of the fans 3a, 5a in such a manner that a measured pressure Pb within the casing 2 becomes higher at a set value P1 than a measured pressure Pa in the external environment, and a measured pressure Pc within the clean chamber 4a becomes higher at a set value P2 than the measured pressure Pb within the casing 2.