The application concerns a handheld medical instrument for analyzing a body fluid, comprising a housing having a cassette compartment for receiving an exchangeable tape cassette, a transport mechanism comprising a manual drive which can be actuated by a user for rotating a tape spool of the tape cassette, such that a test tape of the tape cassette is wound forwards and functional elements stored thereon are provided for successive use, a stop device acting on the transport mechanism for a targeted stop of the test tape in a functional position of a functional element.
