PURPOSE: To enhance the function effective biotechnologically for a user by arranging a mirror consisting of separate parts on the inside surface of a cover for opening of the pocket-watch case.

CONSTITUTION: The mirror 3 is arranged on the inside surface 2a of the cover 2 for opening in the main body 1 of the pocket-watch case. This mirror 3 is preferably the one obtained through the processing of evaporation of gold, aluminum, silver, chrome or other metal on one surface of inorganic glass. The mirror 3 is fixed on to the inside surface of the cover 2 for opening by a method wherein an elastic member 15 formed of synthetic resin, rubber or the like is arranged between the outer periphery of the mirror 3 and the inside surface of the cover 2 or by a method wherein a two-surface bonding tape 24 is stuck to the back surface of the mirror 3, or the like. By this constitution, when the user opens the cover 2, he can find the expression of his face of the mirror 3, and especially for a lady, she can use the mirror 3 effectively biotechnologically for her makeup.