The invention concerns a device for analyzing a body fluid. The device includes a test tape having a carrier tape and test fields for the detection of an analyte in the body fluid, the test fields being distributed along the carrier tape and raised above the carrier tape and a container for the test tape. The container has a seal for passage of the test tape, wherein the test fields have a leading edge which runs against a sealing edge of the seal when the test field passes through the seal. The leading edge of the test fields or/and the sealing edge of the seal at least in parts are angled or curved relative to the transverse direction of the tape.