PURPOSE: To connect a plurality of floor panels without turning a connecting member.

CONSTITUTION: A circular recessed part 14 which is formed through the collection of stepped parts 13 is formed at the corner parts of four floor panels 10, and an insertion port 15 is opened at the center of the recessed part 14, and a fixed hole 18 in the horizontal direction is formed at each stepped part 13. A connecting member 20 which can be installed in the circular recessed part 14 is prepared, and four holding members 24 forming an engagement hook 25 are projectingly installed downward at the lower edge of the connecting member 20, and a pushing spread-in member press-in hole 26 is formed on the inner peripheral surface of the holding member 24. Each fixed hole member 23 in the horizonal direction which is fitted into each fixed hole 18 is projectingly installed on the lower edge surface of the connecting member 20. When the fixed member 23 in the horizontal direction of the connecting member 20 is engaged with the fixed hole 18 at the stepped part 13, and the holding member 24 is inserted into an insertion port 15, and a pushing spreading member 30 is pressed-in into the press-in hole 26, the hook 25 is engaged with the undersurface of the insertion port 15. In this state, four pieces of panels 10 are connected through the fixed member 23.