To provide a hygiene and simple sterilization detecting indicator composition used for sterilization with high pressure steam which is also used easily for sterilization with ethylene oxide gas when necessary, indicates completion of sterilization with a clear color change with excellent sensitivity and precision, and generates no odor, and also to provide a sterilization indicator loaded with the composition.

The sterilization detecting indicator composition contains at least one inorganic substance of 0.1-50 pts.wt. selected from strong acid salts of metal powder, a divalent metal and/or trivalent metal with an inorganic acid and a monoazo dye of 0.01-3 pts.wt. The composition may further contain an organic acid of 50 pts.wt. at the maximum. In a sterilization detecting indicator, the sterilization detecting indicator composition is applied onto a substrate or an object to be sterilized to form a sterilization discoloration layer.