Disclosed is a protective bag that is formed by depositing a light-reflective material and a photocatalyst material on the outer surface of an air-permeable bag. It is preferable that: indentations are formed on the outer surface of the air-permeable bag, and the light reflective material is a coloured fibre and contains first light-reflective particles having a volume average particle size of 100µm-200µm and second light-reflective particles having a volume average particle size of 1µm-5µm.
