To reduce a packaging waste, and decrease the packaging cost while ensuring the virgin sealability.

For a housing case for bookcase type tape cartridge, a lid plate 12 is separatably connected to the mouth edge of an opening 7 with a breakable line 13. At the time of packaging, after placing a tape cartridge T from the opening 7, the lid plate 12 is bent along the breakable line 13, and the opening 7 is closed, and by doing so, the virgin sealability can be ensured. At the time of unsealing, by cutting off the lid plate 12 along the breakable line 13, the housing case of which the opening 7 is under an open state can be obtained, and the housing case can be used for the housing and storage of the tape cartridge T. A cut-off piece 10 is separatably formed with a breakable line 11, at one part of respective front end edges of an upper surface plate 5 and a lower surface plate 6. In a packaging stage, the virgin sealability can be ensured by the cut-off piece 10, and when the cut-off piece 10 is cut off along the breakable line 11 at the time of unsealing, a notched part which facilitates the putting in or the taking out of the tape cartridge T can be formed.