A reagent container is disclosed that is installed in an analyzer for use and stores a reagent supplied to the analyzer via an aspiration tube. The reagent container includes a container body. The container body includes a tubular member with an opening into which the aspiration tube is inserted from above, and a bag-shaped member joined to the tubular member and storing the reagent. The container body comprises a penetration prevention member that prevents a tip of the aspiration tube 90 inserted through the opening from penetrating the container body.