PROBLEM TO BE SOLVED: To prevent a generation of an oxygen gas caused by a contact with a first agent and a second agent leaking into an inside of an outer container from a bag-like object in a dual structure container.SOLUTION: A hair cosmetic comprises a first agent and a second agent, wherein the first agent and the second agent of the hair cosmetic are respectively filled the space for filling with the first agent and the space for filling with the second agent which are provided with inside of a propellant filling space filled with a propellant for pressurization, the first agent containing an alkali agent, the second agent containing an oxidizing agent and the viscosity of both first agent and the second agent is within the range of 7000-30000 mPa s in 25°C.