A cartridge case includes: a tape reel including a hub that is shaped like a bottomed-cylinder and on an outer surface of a base plate of which ring-shaped driven teeth, in whose base part an inclined surface is formed, are disposed; a lower case that has an opening, a ring-shaped contact part and a guide surface, the opening being formed in a center of a base plate of the lower case, the contact part being formed in a protruding state on an inner surface of the base plate so as to surround the opening and having a contact surface that contacts and supports the tape reel at a position on the base plate of the hub outside the driven teeth, and the guide surface, which has a complementary form to the inclined surface of the driven teeth, being formed at an edge of the opening; and an upper case that together with the lower case encloses the tape reel in a rotatable state. The contact part is formed so that an end of the contact surface on a center of the opening-side is positioned closer to an outer circumference of the base plate of the lower case than a virtual plane that extends from the guide surface.