A cap (13) to be mounted to a mouth part of a main container unit of a nutritional supplement container (10) is provided for flowing out a liquid substance filled in the main container unit. The main container unit includes a thin film (16) that is attached to the mouth part so as to seal the interior of the main container unit. The cap can take a first mounted state and a second mounted state with respect to the mouth part. In the first mounted state, the mounted state of the cap with respect to the mouth part is held in a state where an end surface of a hollow nozzle (22) of the cap is located not in contact with the thin film or in contact with the thin film but not pressing the thin film. In the second mounted state, the mounted state of the cap with respect to the mouth part is held in a state where the thin film is broken by the hollow nozzle and the hollow nozzle is located inside the mouth part.
