A boundary layer probe for determining a fluid stream, with: - a measuring surface, which is formed on a probe wall and lies along a fluid stream to be determined in the measuring mode; - an arrangement of measuring obstacles (2a, 2b, 2c), which - are formed in the area of the measuring surface as obstacles, which disrupt the fluid stream in a flow area adjacent to the measuring surface, and in the area of the measuring surface are rotationally symmetrically arranged relative to a center of arrangement of the measuring obstacles (2a, 2b, 2c), - each have an elongated progression of obstacles, which - extends over a respective obstacle length at least sectionally along a curved line, and - is concavely or convexly curved in relation to the center of arrangement of the measuring obstacles (2a, 2b, 2c), and - are arranged in a circumferential direction in relation to the center of arrangement at essentially equidistance angular distances; and - pressure measuring points (3a, 3b, 3c), which are arranged for detecting a respective local pressure in the area of the measuring surface in each case adjacent to an associated one of the obstacles in a radial direction relative to the center of arrangement. - a measuring surface, which is formed on a probe wall and lies along a fluid stream to be determined in the measuring mode; - an arrangement of measuring obstacles (2a, 2b, 2c), which - are formed in the area of the measuring surface as obstacles, which disrupt the fluid stream in a flow area adjacent to the measuring surface, and in the area of the measuring surface are rotationally symmetrically arranged relative to a center of arrangement of the measuring obstacles (2a, 2b, 2c), - each have an elongated progression of obstacles, which - extends over a respective obstacle length at least sectionally along a curved line, and - is concavely or convexly curved in relation to the center of arrangement of the measuring obstacles (2a, 2b, 2c), and - are arranged in a circumferential direction in relation to the center of arrangement at essentially equidistance angular distances; and - are formed in the area of the measuring surface as obstacles, which disrupt the fluid stream in a flow area adjacent to the measuring surface, and in the area of the measuring surface are rotationally symmetrically arranged relative to a center of arrangement of the measuring obstacles (2a, 2b, 2c), - each have an elongated progression of obstacles, which - extends over a respective obstacle length at least sectionally along a curved line, and - is concavely or convexly curved in relation to the center of arrangement of the measuring obstacles (2a, 2b, 2c), and - extends over a respective obstacle length at least sectionally along a curved line, and - is concavely or convexly curved in relation to the center of arrangement of the measuring obstacles (2a, 2b, 2c), and - are arranged in a circumferential direction in relation to the center of arrangement at essentially equidistance angular distances; and - pressure measuring points (3a, 3b, 3c), which are arranged for detecting a respective local pressure in the area of the measuring surface in each case adjacent to an associated one of the obstacles in a radial direction relative to the center of arrangement.