To provide a surgical endoscope apparatus capable of maintaining airtightness even though soft endoscopes with various outer diameters are passed through a trocar, in which how to use is simple, and which can be easily used.

Magnets 110, 32 generating attraction force by magnetic force in a radial direction between a flexible tube part 11 and the trocar 30 with the flexible tube part 11 passed through the trocar 30 are arranged in the outer peripheral wall of the flexible tube part 11 and in the inner peripheral wall of the trocar 30, the flexible tube part 11 is passed through the trocar 30, the magnet 110 of the flexible tube part 11 side and the magnet 32 of the trocar 30 side are attracted to each other, thereby the outer peripheral face of the flexible tube part 11 and the inner peripheral face of the trocar 30 come into close contact with each other with at least one of them expanded.