A tape printing device comprising: a cartridge loading section in which a tape cartridge is loaded in an unloadable manner; and a push switch which is provided in the cartridge loading section and detects the loaded tape cartridge; wherein: the push switch has a stem which is energized in a protruding direction by a build-in spring, the stem in an actuated state energizes the loaded tape cartridge in a direction intersecting with a loading direction, the tape cartridge has a cartridge case formed by a lower case which comes to a rear side when the tape cartridge is loaded in the cartridge loading section, and an upper case which comes to a forward side, wherein at least one section to be detected is provided in at least one position on an outer circumferential surface, corresponding to the push switch, characterized in that: the section to be detected includes a recessed portion concavely formed in an upper peripheral wall portion of the upper case, a thick portion formed in a lower peripheral wall portion of the lower case, and a slide portion concavely formed on an outer surface of the thick portion, the slide portion has a contact surface and a release guide slope connected to an upper side of the contact surface, when the stem is situated in the recessed portion or on the release guide slope, the push switch is OFF, and when the stem is in contact with the contact surface, the push switch is ON. a cartridge loading section in which a tape cartridge is loaded in an unloadable manner; and a push switch which is provided in the cartridge loading section and detects the loaded tape cartridge; wherein: the push switch has a stem which is energized in a protruding direction by a build-in spring, the stem in an actuated state energizes the loaded tape cartridge in a direction intersecting with a loading direction, the tape cartridge has a cartridge case formed by a lower case which comes to a rear side when the tape cartridge is loaded in the cartridge loading section, and an upper case which comes to a forward side, wherein at least one section to be detected is provided in at least one position on an outer circumferential surface, corresponding to the push switch, characterized in that: the push switch has a stem which is energized in a protruding direction by a build-in spring, the stem in an actuated state energizes the loaded tape cartridge in a direction intersecting with a loading direction, the tape cartridge has a cartridge case formed by a lower case which comes to a rear side when the tape cartridge is loaded in the cartridge loading section, and an upper case which comes to a forward side, wherein at least one section to be detected is provided in at least one position on an outer circumferential surface, corresponding to the push switch, characterized in that: the section to be detected includes a recessed portion concavely formed in an upper peripheral wall portion of the upper case, a thick portion formed in a lower peripheral wall portion of the lower case, and a slide portion concavely formed on an outer surface of the thick portion, the slide portion has a contact surface and a release guide slope connected to an upper side of the contact surface, when the stem is situated in the recessed portion or on the release guide slope, the push switch is OFF, and when the stem is in contact with the contact surface, the push switch is ON.