The mobile detection device (2) includes a light source (212) that generates light having at least a wavelength component necessary for detecting a curved shape in at least one detected part (211A), and the light from the light source (212). A flexible light guide member (211) including at least one detected part (211A) that guides light, and a photodetector (213) that detects light emitted from the light guide member (211). The fiber sensor (21) which has these. The mobile detection device (2) outputs an output signal of the photodetector (213) or a signal of at least intermediate processing information in signal processing for obtaining a curved shape in the detected part (211A) from the output signal. The communication unit (228) includes a signal processing unit (22) that wirelessly transmits to the fixed signal processing device (3). The fixed signal processing device (3) includes a signal processing unit (31) that obtains information related to the curved shape of the detected unit (211A) from the signal received by the communication unit (313).
