To simply and smoothly perform the rotation operation of a panel by using a multi-spindle gear on a connection part when the partition panels are connected.

A rotary shaft is directed on the side end part of the panels P1, P2 to the vertical direction to fix gears G1, G4 so as to be impossible in rotation, gears G2, G3 are arranged so as to be rotated around the periphery while the gears G1, G4 are engaged on the outside, the gears G2, G3 are mutually engaged, and the rotary shafts of each gear are connected in the state that they are supported by a support member on the same straight line.