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. <EOS>