To provide a pipe conveyer in which a twist or depression of a rounded conveyer belt is simply and efficiently detected by effectively using permanent magnets and the closability of the conveyer belt is improved. [MEANS FOR SOLVING PROBLEMS] A conveyer belt (3) is rounded into a pipe, and both side edges (3a, 3b) of the conveyer belt (3) are laid on one the other. On both opposed surfaces of the edges, permanent magnets (6, 7) attaching each other are provided. A fixed body through which the rounded conveyer belt (3) passes is provided, and a plurality of magnetic sensors (8) are so circumferentially arranged on the fixed body as to surround the conveyer belt (3) and to detect the magnetic force strengths when the permanent magnets (6, 7) pass by the fixed body. Twist detecting means (11) for comparing the detected magnetic force strengths and detecting a twist of the conveyer belt (3) from the position of the magnetic sensor (8) which has detected the peak value (P1) is provided.